According to the developer site, the Web Engine powering the Apps and I assume the Web Browser on WebOS is built on version 53 of Chromium (for 2018-2019 models) or Chromium 68 (for 2020 models). Version 53 is from 2016, and 68 is from 2018. The current version is 85.
The latest version of JavaScript used by modern websites (ES7) is only supported in version 68 and above, and there has been some evidence that although WebOS is using version 53 of Chromium the browser is not fully compatible with the previous JavaScript version (ES6).
The result is that by keeping the WebOS browsers locked in older Chromium bases users will find more websites become unusable on our Smart TVs as old sites are upgraded to new versions and new sites come out. This is not an issue for Android based Smart TVs where users can install current web browsers of their choice.
LG is supposed to be a leader in technology- I have been incredibly pleased with my LG phones and other appliances but am extremely disappointed with the proprietary WebOS browser on LG Smart TVs. IN 2020 it is unacceptable thar such a fundamental function of a smart device (web browsing) is so out of date.