Do you, as people of the general public, and as a gamer, really care about "buzzword" design tropes for games? My point being when someone says "this game is a soulslike." I don't really like this one-note sorta offhand denotion of a game. Do you care if an up and coming game is a "Soulslike" or "DMC style" action game? Do those keywords in articles, and sometimes even steam pages themselves, entice you to play the game more?
It isn't because of keywords in articles, but because of preferences over time. Keywords/buzzwords help players identify types of games relating them to something else they like.
There are trends, sometimes not only in games but also in movies or tv shows where during a limited period of time (sometimes a year or two) some theme or setting hits hard. Stuff like 'superheroes', 'western', 'cyberpunk', 'zombies', etc. often because there are one or two hyped hollywood blockbusters that hit hard, maybe around the same time that a huge game or tv show also hit hard. This make people who like that wanting more, and smaller games in that setting may perform a bit better than usual during that theme or setting.
But at some point people gets saturated and they stop working.
Similar happens with game genres: battle royale, souls, roguelike, hero shooters... they had a trend when they kicked hard that also benefited smaller games, until people got saturated and the hot trend started to be something else.
Game genres, like settings, still get an audience, a niche, outside trends. But normally heavily focused on the fan favorites and with a large competition, so it's difficult to compete. Normally games need something to standout like a super polished gameplay or a great/different/unique art style, some game mechanic and/or music style.
It is also common that when devs start to develop a game that is trendy (case of Concord in 2016) but when released the trend is over and tank (case of Concord), often because the game didn't know how to appeal that target user offering something unique that helps the game to be more appealing than the similar ones.
It is super hard to make really new and unique things appealing to the people, often it is a safer idea to mix stuff that works from different genres that appeal to a similar demographic. Mixed in a way that nobody (or almost) did before. As an example: Stellar Blade mixed hack & slash with souls-like in terms of gameplay/combat, and waifus and dystopian scifi in terms of theme/settings/aesthetics. Did it in a unique way that found its audience.
Others instead tried to make only soulslike with a traditional soulslike gameplay/combat and dark theme/setting, so felt just like a cheap copy of the FromSoft ones.
Elden Ring had the popularity of the devs and fans of the genre, but polished their formula and mixed it with the open world, a concept that also appeals that audience helping it differentiate and feel better than the other soulslike, and found a huge succes.
So it isn't buzzwords, but preferences and trends. Which in many cases are time limited unless they offer something extra that makes them stand out.