I have tried those which come default on Vivaldi 3.6. Inferior to multiple tab rows.
Why would I want 300 tabs open? To me that means one is doing something wrong.
But no means. If did not have so many it would hinder productivity. In one browser used mainly for forums and related research than I have tabs of sites I want to have handy, plus ones I am engaged with or want to check on. On another browser for shopping I have many tabs for items I regularly buy (bike parts, etc.) depending on the deason. On another browsers I have tabs for bills to pay and good movies (hard to find) when I too tired. On another browser I mainly just do Quora, and with my stiff arthritic fingers I do a lot of copying and pasting in response to similar questions, adapting them as needed. When you have a lot of irons in the fire, and can easily fit 6 rows of identifiable tabs, 25 across, differently colored according to source (as seen in post 105) on a 23" monitor, then it is far quicker to have everything handy to quickly access. Thank God.
Thats why you have bookmarks. So you don’t have to consume the memory and other resources to keep 300 tabs open. Even if a browser does some type of lazy, deferred loading, that still consumes resources. I can have all those in a side window and then instantly click or enter a keyword and then click. Why would I want the top of my browser window wasted by 6 or 8 rows of tabs?