Check out container tabs. Either built-in (activate with `privacy.userContext.enabled` and `privacy.userContext.ui.enabled` in about:config) or if you don't mi

Check out container tabs. Either built-in (activate with `privacy.userContext.enabled` and `privacy.userContext.ui.enabled` in about:config) or if you don't mind some telemetry (non-sensitive stuff but YMMV) and random updates you can use their Test Pilot experiment https://testpilot.firefox.com/experiments/containers https://testpilot.firefox.com/experiments/containers (or you can just grab yourself an XPI and update on manual basis).