I'm been trying various browsers lately, especially running them on a Raspberry Pi 4 (4GB RAM) and Pentium M laptop (512MB RAM).

Pale Moon generally is quite usable, but JS heavy websites seem to be its weakness. Surprisingly I found that Konqueror nowadays seems the most optimal even when not running KDE Plasma. It renders quite fast, handles JS quite well and even runs quite good on the Pentium M. It only misses private mode.

Of course Dillo and Links 2 are nice for even older systems.