I can't speak for anyone else, but for me, there's a number of factors
- Its rather bloated, opening numerous tabs has a negative consequence to system resources.
- Then there's the information it collects and sends back, I'm just not comfortable with how Google collects my information and sells it. I'm more privacy minded so I largely try to avoid companies that actively sell my data, and Google is the worst. Actually a case can be made that Microsoft is the worst given this information)
- Given they're largely a monopoly, they tend to behave in anti-consumer behavior
- Manifest V3 changes where they're actively working on blocking/preventing ad blocker plugins
- Every update, Chrome takes over certain extensions, for example instead of letting PDFs be opened by Acrobat, Chrome takes them over and I have to constantly reset the default app back to Acrobat (this may be a Windows only phenomenon)
There's others, but those are the bullet points that I think bother me the most. As I mentioned, I have chrome installed on my computer, and I still use it, mostly because there are sites that don't play nice with FireFox