Can’t add much to @kurt.braeckel ’s excellent advice, but I would also look hard at any unstructured riding. My rule is no more than 3 days per week with intensity, but 2 of those days need to include quality structured intervals. So, that rule basically means you only have one day per week for a group ride or race (unless you can get your structured work in prior to group ride start). This is a tough one for me to follow, but my training always suffers when I violate it. I can’t go as hard on Thursday when I do the Wednesday group ride, even though it’s a pretty easy ride with less tss than the z2 I should be doing. If doing multiple group rides per week makes you happy, that’s a good reason to keep doing them, but it’s likely holding back your progression.
Wanted to provide an update.
Gain wise I went from what I think was an overestimated 260 watt to 265. Small so far but I have seen my VO2 max ability get better.
Also raised my w/kg by losing another 5 lbs. maybe 10 to go there. So maybe that’s why my ftp isn’t going up, diet is in a calorie deficit. But I want to hit 160 before I try to break even calorie wise again and I’m at 165.
Doing 200 miles a week. Trying to keep up with the more disciplined z2 days. So w/kg went from like 3.35-3.5ish with that gain and weight loss.
I’ll post more updates later if I see more gains. If not I may bother for advice again. Thanks!
Congrats on the gains, and yes, keeping the balance of eating enough/correctly/properly is a struggle for almost all of us.
For how long have you been riding?
Cycling is a tough sport and essentially an endurance sport. It requires years of construction, brick on top of brick. I see your point of "how that guy rides 6hr/w and he’s 4.5w/kg. But then you realize that the guy is riding for 10, 15, 20 years consistently.
Don’t be discouraged or frustrated because you didn’t see your numbers through the roof. Riding consistently, even without any training plan, is better than no riding. And you’re building your bricks for sure. If you haven’t yet, sign up for a TR plan and follow it closely, you’ll see good improvements.
Good stuff. Underrecovery is way, way more common than overtraining (and yes they’re different). 
Seems like it. Just did Big Sugar, started at the back due to being late and needing to pee, but that gave the opportunity to pass people nonstop.
Nice ego boost to always pass people on the hills while not going 100%
Had issues putting out consistent power later though, i know why now. Turns out I was sick, lost my voice by the end, took monday off work i felt so bad. So I guess thats improvement if I can manage such a hard gravel race while sick.
So this is recovery week. May not ride til wednesday and then itll be easy.
I identify with your original post re: plateau. Most of this has been covered, but my experience has been:
-Really important to periodize and respect those rest weeks. It’s always hard if there’s a fun group ride you want to jump in on what’s supposed to be rest, but taking time to recover is super key.
-Likewise macrocycles, i.e. take a few week “off season” or mid-season break. Fatigue is cumulative, and if you’re riding very consistently you may actually forget what it’s like to be fully rested and recovered. That can be surprisingly hard; “I’m de-training! I’m gaining weight!” But it will actually help in the long term. I often make the mistake of considering a vacation to be my rest, but my vacations often include jet lag, hiking, dubious dietary decisions etc. Not really ideal for recovery!
-For me, structured training is far more valuable than unstructured group rides. I find I can get pretty fit on group rides, and they’re lots of fun. But they tend to cause more fatigue than training adaptation in many cases, and getting past a plateau is best done on structured training. Up to you how important that is, there’s always a trade-off between mental health/enjoyment and fitness gains.
-How old are you? I just turned 45, so am beginning to recognize that just maintaining FTP and w/kg year-on-year can be considered a gain.
I just turned 40, and yeah I have been really trying to do rest weeks better, not that great at it yet though. Only good social time I get is the saturday/sunday rides, saturday being really fast then I add miles onto it, Sunday being moderate. Maybe Ill try and make friends with the B ride on my rest weeks instead. I also try to take 1-2 weeks fully off per year, generally family vacation type stuff.
Recently started tracking calories a bit closer and upping protein intake, not too crazy but dropped from 170 to 165, so thats one way to raise your w/kg. Ideally drop 10 more and stop there.
This summer I have been getting about 200 miles in per week, up from maybe 150 last year. I have better endurance but i think the extra unstructured riding didnt really help as much as id hoped. Seeing the final results from Big Sugar shows I have a lot of improving to do, granted I didnt feel great but I was barely in the top 2/3 for the 100 which seems crazy to me. But the competition there is a lot stiffer than the usual 100 miler for gravel with how hilly it is I guess. Hopefully itll keep going up, since it went up 5-8 watts over the last month after a decent amount of stagnation. Just frustrating to ride and train so much to be stuck around a meh 3.3-3.5 w/kg.