Something being open source doesn’t automatically make it safe to use. Sure, it means it’s easier for people to check for security issues, but how many people actually have the knowledge and the time to do it? And even then, take the log4j vulnerability from a while ago, it’s been present in the code since 2013 and only reported in like 2021.
I wouldn’t label things they changed compared to 5e rules as necessarily broken, unless the way they say it’s implemented doesn’t actually match what’s happening.
I picked half elf as race initially because I was used to the +2 +1 +1 spread they get, which isn’t the case in the game, or hypnotic pattern, which only lasts 2 turns instead of 10. Is the game broken? No, it’s just me assuming stuff will be 1 to 1 to the 5e rules. And it goes both ways, took me a bit to realize they don’t follow the spellcasting rules to a t, and you can cast leveled spells with both your action and your bonus action.