Try guild wars 2.
You can play without completly downloading it.
Its f2p and you can explore all together, since every starting map gets unlocked no matter what race you pick at the start.
It is also very easy to learn and you can even outlevel each other if anyone wanna keep playing in private, since you get levelcapped depending what map you are in.
Brilliant game design all around and still one of the best multiplayer games out there IMHO.
If you want to scratch a similar itch, and have not already, try Guild Wars 2.
It does have microtransactions, but only because they have no subscription fee and they are mostly cosmetic with a few rare exceptions.
It also has no FOMO except cosmetics from certain festivals, which you can also buy in the next year.
It is still the best MMO on the market IMHO, because it values your time and money compared to other games in the genre.