Everyone is a sprcial snowflake. Pain labeled as a syndrome can have multiple causes in different ppl. One YouTube video, or what worked for you won’t work for everyone else. Half my patients with back pain go on YouTube and come in worse because they followed some “3 EXERCISES TO CURE BACK PAIN!” That actually make them worse.
Trust me. I deal with this everyday. Yes, tightness of the TFL can play a role, but what if they have hamstring tightness or patellofemoral tightness as well? The IT band inserts on those structures distally at the knee as well. So if you fail to address those causes you could stretch or roll your ITBand all day and have limited results. Same with bike fit. You could have a loose TFL but kf your clear and shoe position places you in too much valgus it can cause it.