I will preface this by saying I still love overwatch, and I think it can be a very enjoyable game if you enjoy competitive shooters and don't give a shit about cosmetics. The game costs 10dollars every 3 months or so if you want all gameplay mechanics at release.

Ow1 was expected to be a huge failure, designed to recoup costs from a different project that was never released. Because of this it sold for a flat fee and gave out lootboxes like candy. It ended up being a massive smash hit and a few years in they announce ow2, just as some of the competitive limitations of the game started to show up.

Ow2 got delayed a bunch and ow1 stagnated without new content. When ow2 finally released it had a rocky start, it went f2p and it also didn't deliver on some of the promises and marketing hype. Most of the beloved public faces of the devs left the company and They removed a number of features from the old game, and it was initially quite buggy although I think for the most part they have all been readilded by now (only thing i can think thats missing is lfg, which was frankly aweful in ow1). The cosmetics were given out much less freely and have absurd prices. They also made new heros cost money (although during their season of release you could grind abiut 20hrs to get it, or wait until the season ends and get it in a few hours). They made some controversial game design decisions including reducing the number of players per team by 1, and removing some cosmetic features that were mostly ignored in ow1.

The biggest of which was a pve mode, which some people extrapolated to believe was going to be a whole single player game. For some this was the primary reason to wait for ow2. This was heavily scaled back, although this season we are now seeing the remnants of what that looked like a few years late and without some of the biggest features (like skill trees).

All this happened while blizz was having a massive sexual misconduct scandal, which obviously garnered a lot of negative sentiment, but also made the lawyers lock down all communications (ow1 had a very open and informal set of communication with the community), shook up their dev teams, forced them to rename a character (he was named after one of the rapists) and made them the victim of several ddos attacks.

There's also a bunch of stuff with the pro scene that I dont follow much, but essentially in ow1 they monopolized the pro scene which they had total control over, they forced teams to use country / city names instead of the standard egaming organization. This pro scene has, by all accounts been a big failure and now they are paying the engaging orgs to leave the league so they can kill it entirely.