Party-based game isn't something bad, but it's something that you need to unlearn if you, well, ain't running/playing a party-based game.
To be more specific- this isn't a judgement about party-based gaming. I mean, it is a judgment about parties. I love parties. Party party party. To quote the great RPG theorist, Andrew W.K., in his seminal work, Ima play some D&D- You? "So let's get a party going, let's get a party going! Now it's time to party and we'll party hard, party hard! Let's get a party going, let's get a party going! When it's time to party, we will always party hard, party hard! Party hard, party hard, party hard, party hard, party hard, party hard, party hard ... PARTY HARD!"
Ahem. But assuming, arguendo, that TTRPGs are a social game, that involve multiple people (usually four or more), then it makes sense that the "party" is such a desirable state-of-being within the game, as it provides for a reason for the people to be RPing together and a unified purpose, not to mention a good reason for such concepts as "sharing the spotlight" within the game.
Whether by luck or accident, I don't think it's a big surprise that .... we all like to party hard party hard party hard!