I have a rule of doing 20 XP per day, and I kept that rule for more than half a year. Maybe the price is also a factor, but I never managed to keep that pace for Khan Academy when I tried it. You can check their current courses here: https://www.mathacademy.com/courses

I think the topics and curriculum are more serious, and I would definitely recommend it if you have kids or are in highschool/uni. I'm 37 now and only do it to keep my brain sharp and build my mathematical intuition and I think is great for that due to its focus on practice and spaced reviews.

I think they have a 1-month trial, and you get your money back if you cancel within 30 days if you want to try it.

That said, on higher levels there's some cruft that trains mechanical skills, and that's on subjects that are needed only in the scope of the US system. For Europeans these should be optional, alas they are not and this adds a lot of tedium and hassle to an otherwise rather frictionless process.

If it improves your learning efficiency by just 10% then it's worth it.

(My son uses math academy 3-5 hours per week.)

This review lays out how you should think about the costs and benefits: https://jonathanwhitmore.com/posts/2024-09-10-mathacademy/in...