I've been using https://simplelogin.io for this. Paid for premium and I think it's well worth it. You don't want to use an email that will disappear in a few days if you need to actually receive mail from whatever service you're signing up for.

I don't know if I like this change. Not allowing for sideloading means a reduction in user freedom, sure, but how much freedom does the average user care to have anyway? With the state of Apple products as it is today, I would definitely recommend them to someone who isn't technologically savvy over something that grants more freedoms because of how fool-proof it is. For the rest of us who know our way around this stuff, we have Linux. The lack of freedom in Apple products doesn't take away from the freedoms of Linux users.

Don't most distros have access all desktop environments? I'm assuming OP is asking about the default DE.