other private and sustainable software
Please for the love of god just use Firefox. It’s such a good piece of software and the company also does amazing pro-consumer stuff.
For email, I personally use hey, which has some nice power-user features in a pretty package, but I’ve also heard really good things about proton mail.
For search engines, Duck Duck Go has been beating my expectations, to the point where I often like the DDG results over the Google results. I sometimes do use Google as a backup, but I don’t necessarily think Google has better results, just somewhat different ones.