I like to bind meta-1 to meta-9 to switch to the nth app on my desktop bar. This means Discord (which is always meta-4) will always a keypress away for me, while Firefox (meta-1) requires me to find the right window and the right tab.
(Also, I routinely close browser windows I am not using by force of habit, which means I'd need to wait a load time every time I want discordapp.com.)