We make a persistent browser RPG, and it is not a RuneScape substitute. It has no fantasy setting, no rendered world, no combat you watch happen. If those are what you are looking for, close this tab and go and find a graphical MMO - you will be happier and we would rather say so than waste your evening.
Where the overlap is real: it runs in a browser with nothing to install, progress is measured in months, the numbers are visible and worth optimising, there is a player-run economy, and there are other people in the world affecting what you can do. If that list is what you were actually chasing, the genre is worth an hour of your time even though the setting is different.
The specific game is The Fifth Family - a mafia RPG with 100 crimes across 10 city districts, mastery progression that unlocks rarer loot the more you repeat a crime, 100 careers spanning levels 1 to 199, stat-driven PvP, a player market, families with territory, racing, smuggling and heists. Browser plus native iOS and Android on one account, free to start.
If "browser game with real progression and real people" was the search behind the search, that is what this is. If it was "RuneScape but different", it is not.