I asked AI which ones I needed and reduced the number of extensions (from around 8 or 10 to 2.)
Extensions can be (and have been) an attack vector for malware. There have been many instances of extensions exfiltrating a user's data. Browsers typicaly run in a sandbox, but it's not unheard of for them to use memory after it was previously used as a path to exploit the system as a whole, albeit less common today.
So, I strongly suggest using only extensions that you trust, from people you trust. Spend some time looking up who wrote the extension, check to see if it's open source, verify that it's from an actual business, and stuff like that. They've been known to even use your bandwidth to relay spam, to do DDoS attacks, or to rent your IP address out for nefarious purposes.
Extensions are great. They make life easier. They make life better. It's not entirely about quantity, but about trustworthiness.
For example, I'll happily use my VPN browser extension. I know where it comes from, and they're a real business that has been independently audited, stood the test of time, and even the extension is open source.
I'll immediately install anything Raymond Hill (gorhill is his username) because he has a huge history of integrity and efficacy.
You know, that sort of stuff...

