Solasta didn't not sell huge numbers because of its system and mechanics. It sold small because it was the first project of a small indie studio made on a small budget.
Whilst this is undoubtedly true to an extent, wasn't it also a Kickstarter? In which case if the concept was so popular they would have secured more backing?
Because they were a new and untested studio? Because by the time Solasta's kickstarter started BG3 was already a known thing so it's not as though people thought it was their only chance? Because it just didn't get a lot of reach? Because record-breaking kickstarters are an anomaly and not every good or great idea is going to break records? Even Larian when they did their kickstarters, they had already been making games for years (though I had never heard of them before personally) so it's not like they were literally unknowns with no body of work to look at and say "yeah, these people could make a game." I feel like the question of "if this was a good idea, why didn't it make tons of money?" is an inherently flawed one because good ideas fail all the time for loads of reasons, good and bad. And Solasta didn't even fail. It was popular and successful enough that the devs clearly felt confident in putting out three or four more DLCs for it and a lot of free content updates.
Okay, this is a slight tangent from the rest of the thread and conversation. I feel like in gaming there's this expectation now that if a game is really good then it'll explode and be super popular and everyone will be raving about it, and if that doesn't happen then the game wasn't actually that good. And I hate that idea. People were talking about Hi-Fi Rush and that game just dropping from nowhere and being super successful compared to the big budget Forespoken. Well Hi-Fi rush was still made by a really successful, popular company that had put out lots of great games in the past. The fact Solasta didn't become the biggest thing in crpgs doesn't mean that its premise is inherently unfit for the mainstream or that it's at all inferior or anything like that. It just means that it was a game built with a small scope, by a new company making their first game. Using that as an example of why BG3 being more loyal to 5e because it didn't catch fire is an unfair comparison that implied widespread validation is an inherent mark of quality, when really a game can just have its niche, be in that niche and even if it's good, even if its concept could be expanded and made mainstream, that's just not what the devs tried to do, so it's no one and nothing's fault if it doesn't get talked about a whole bunch. Hell, look at Owlcat. Their first game, Kingmaker didn't get all that much talk relatively speaking either. But their second game? Even bigger, it got more buzz and discussion and even now it's more talked about and regarded than Kingmaker.
I'm sorry, I kinda went off on a ramble, this might not all make sense, but I had to put these thoughts somewhere so I don't explode.