Tab management is a very active area of extension / plug-in development and while there are certainly compromises, there's no silver bullet for making 20, 30 or 100 tabs look anything other than chaotic. That said, if you're a Chrome user addicted to tabs, but not that keen on any of the available extensions, you can give the browser's experimental "Stacked tabs" feature a go.
As Additive Tip's Waqas Ahmed explains, activating stacked tabs is easy: just hit up
chrome://flags by typing it into the address bar, scroll down until you find the greyed-out "Stacked tabs" option and click "Enable". You'll then need to restart your browser.
Once you hit about 13-14 open tabs, they'll start stacking to the right and once you hit around 24, you'll have them piling up on the left as well. It's definitely nicer than having a bunch of extremely tiny, unidentifiable tabs, but it's still no substitute for something like Tab Outliner.
It's one of those settings you'll have to use for 15-30 minutes before you can make a clear decision on if it's for you, but you don't have much to lose by giving it a try.