I did all my working out in my teens/20's, playing sports, and going to the gym regularly. Have still retained most of those muscles and strength, I've just insulated them pretty well over the last 20 years....

Upper body still strong, but I've noticed my legs have the most atrophy since it's been about 12 years since I quit hockey. Nowhere near the leg strength I once had. Core a bit squishy too.....I've really noticed that one a lot lately with more back trouble. Gotta work on strengthening that core again....
New job has me pretty active again though, and the lbs are coming off. Down 15 since last fall/winter, and probably lost more fat/gained a bit more muscle since. Don't think I'll ever get down to around 195/205 again without a lot of work and effort, but I'd be happy to get down to 215/220 again and can see that being a reasonable goal in the next year or so continuing on the path I am now without making a lot of major unsustainable changes. When I get there, 200 might seem more reasonable, but from here it seems a bit too far yet. Sitting around 250 now @ just under 6'. About the only cardio I do anymore is walking rounds of golf. Never had any interest in running, but do enjoy riding a bike. Just don't have much time for it. Work usually has me well over 10k steps a day, sometimes 15-20k+, not to mentions stairs.....lots of stairs, and carrying heavy stuff up/down. Stark contrast to my old job where I basically held down a chair for 50-90% of my day staring at a screen.
Eating good quality food in the right proportions for YOU, is I think the most important thing anybody can do to lose/maintain weight. Sadly I'm a feelings eater, and that is difficult....Happy? lets celebrate! In a depressed funk? Kill a bag of chips on the couch every night. Doesn't take long to over consume calories.....Beer's a big one too. Not much drinking anymore aside from a well earned Guinness once in a while.
The last time I got serious about losing weight was in 2012 and I dropped from around 235 to 200 to get serious about racing and maintained that for about a year. Then I had kids and started living a pretty sedentary lifestyle, and all my sports became calorie positive.......It's been a pretty steady 3-5lbs a year since. Covid packed on 15 easy....