For those who are stuck with an old hardware / browser

You can try booting your computer with a pendrive or bootable CD with the Slax distribution (www.slax.org - ISO file 270Mb ). I have tested it with 512Mb of RAM and it is light and fasst; includes the Chromium 73.0 browser where Lichess works correctly.

There's also an option of making a virtual machine with some light-weight linux distro. Yeah, it's kinda pain in the bottom to do so just to play chess, but it's reliable and doesn't require you to boot into a different OS.