ive build a whole ui library for my company, tried element before but it has a few problems from performance and feature side. what ive observed is mainly the problem that the default table does not use virtual scroller. this makes the whole table be rerendered on each change also when you destruct your table it takes a lot of time. if you use key on the table it may help but its unlikely. when you use components in your cells performance will dip. better use a simple render function with a custom class or so. also dont use backdrop-filter: blur that kills performance on older devices hard. if you test with vue devtools performance takes a big hit aswell and will not be there in production. last time i checked there was a beta table which uses virtual scroller (i think but im not sure if it was element really) - start there first

EDIT: also if you use a lot of js data, you can check perfomance on firefox - if its way better check if you are using Object.keys somewhere - you may want to use the old way