Happy birthday, I guess.
I've used Firefox as my main browser since 2007. In that time it's mostly only become worse. It peaked at 3.x and only went downhill from there. I have a love/hate relationship with it. I love that it still isn't (yet) chrome and gives me a less-google influenced option. I hate that it's been in a death spiral for years.
The foundation has made blunder after blunder, forgetting why people want to continue to use Firefox and instead spent the best part of the last 13 odd years focusing on copying Chrome, which if I wanted to use, I would use instead.
They started by copying the chrome interface, which I never liked. Hamburger buttons suck. It can be (Mostly) reverted, but it's still a pain.
They then added features nobody cares about like Pocket, Firefox Accounts, Suggesions... all more reasons to track you, but at least unlike chrome they are removable.
Then they copied the addon API so now Firefox addons are just as crippled as chrome ones. Support it by all means for compatibility, but don't make it the only option when we used to have better!
In recent years especially website compatibility is starting to become an issue. I don't know how much of this is down to Mozilla and how much is down to lazy "web developers" who have never even heard of firefox let alone test with it. Microsoft sure don't care, Teams openly refuses to work in Firefox. Almost made me late for a job interview!
Chrome is exactly like what IE used to be in the mid 2000s, only worse. It's got its tentacles in everything, forcing you to use it by being embedded into other things (Thanks Electron!) and it's actively spying on you rather than just enabling others to do it through being incompetent.
I'm keeping an eye on Ladybird. It's the sort of project we really need in the browser space. Fresh blood. Mozilla still make the best browser but they've been braindead as a company for a very long time and it's inevitable it will go the way of Netscape. They didn't learn.