Absolutely…taking a block of training and focusing on a weakness is almost always a worthwhile effort.
If running is your strength, you aren’t going to lose that strength by putting it on the back burner for a few months.
Offseason is the perfect time to do this…if you can spare a full year and just focus on the bike (potentially including bike races if you are comfortable with that) is even better.
Good buddy of mine is a fantastic runner (runs a ~3:05 IM split and has KQ’d twice). He is a good cyclist but not great. His FTP is much higher than mine (30-40w) and we weigh about the same, but I am a much stronger cyclist overall. If he took a year and just focused on the bike, he would absolutely crush everyone.