Not all have powerful computers able to handle a lot of open tabs in Firefox.
Maybe we can have somewhere in the toolbar giving the user a visual hint on how many tabs are currently open in Firefox? And maybe, an option to limit the number of open tabs in each browser session (so that your browsing experience will not slow down).
Reducing the number of times I need to key in this in the awesome bar:
about:telemetry#search=browser.engagement.max_concurrent_tab_count