Most accurate air gun I have at ranges past 100 yards is my Panthera 25 with a 600mm barrel. Around here our ground squirrels are slightly smaller than a dollar bill when standing straight up. I can kill them pretty reliably out to about 140-150 yards with this gun as long as the wind is minimal or nonexistent. Get any further than that and the percentages drop off to the point that I wont take the shot now that I know my limit.
I would suggest you buy the best air gun you can afford and make sure the make and model has a reputation for shooting slugs well. Once you have the gun and a slug performing well @ 100 yards, start stretching the set up’s legs and when you cannot reliably hit a business card you know what your limit is.
200 yards on critters is a long shot for anybody. The shots you see on YouTube are highlights and omit the misses and wounded animal that got away to suffer a slow death that occurred while trying to make the shot they show you.