I can relate to your problem.
I was an overweight kid and have gravitated towards easy weight gain my whole life.
I tend to gain weight in my legs, bips and ass first too.
It has taken years to build a modest level of strength and hold muscle, currently (320 Bench, 210 OHP, 475 Deadlift, 370 Squat) at a slightly chubby 6’ 215lbs. I can also easily do sets of 10 for various forms of pullups.
With that level of strength I have a 16" flexed right arm.
You just need to stick with it much, much longer: Years, decades, a life time.
You have vastly underestimated the amount of time it takes to accomplish your goals.
Most short term transformations you see on the web are people cutting weight and showing their abz.
Losing fat is easy to do. Gaining muscle and strength is a much slower process.
I assume the people you are comparing yourself too have athletic backgrounds and were probably training through sports and calisthenics their whole lives. They may also be more genectically gifted, both structuraly and hormonally.
If you didn’t know how to read 18 months ago, would you expect to be writing novels at this point. At this point you have just started to become physically literate. Within a few more years, you should have a respectable base and , ironically, within a decade people will be telling you you’re lucky that being muscular and strong comes so naturally to you.
Everyone has a different starting point and potential.
Don’t worry about how you stack up, just focus on improving yourself.
I have found in training, business and life in general if you focus on the process and recognize that immeasurable amounts of hard work and time are necassary for true success, the results will take care of themselves.