I suppose it depends on why you’re learning a thing. If you’re seriously trying to learn a language then using a variety of tools that cover different aspects of language learning is vital.
For me and Duo (Spanish) I’m on a 438 day streak and I couldn’t talk to someone but I could read enough to get by, but I am not learning Spanish to learn Spanish. I know that sounds ridiculous, but learning new things for me is more about the journey and having fun along the way, without having any pressure of this is my end goal. I just like learning different things and often just move on as my curiosity changes.
That’s not to say that I don’t learn some things with an end goal, as an example I’m a junior software developer so I had to be more structured with that.
Duo has 6500 Spanish words too.
I do.
I use SimpleLogin and ProtonMail.
Some sites have I’ll actually know you’re using SimpleLogin though and just say no, but they’re few and far between.
You could also use your own domain if you have one or buy a cheap one.
Then you can create as many as you like and just kill them as and when you need.
SimpleLogin has plugins for all browsers and phones so it’s not too difficult to create new addresses.