I wouldn't say it's better to avoid compression or eq - it just depends on what you're trying to achieve! That being said, before setting levels on your interface always test (if possible) the source you're recording so you don't get clipping during the tracking process. If you're using samples, they should be pretty cleanly recorded (unless stylistically distorted etc.)

I mixed for years without gain staging and I wouldn't say it ruined any of my songs... I just used my ears. But I will say it has been helpful to quickly get new sessions to a good, roughly balanced mix before getting into eq, compression, reverbs, delays, etc etc.

I'll give a simple example - if I have a bunch of tracks I'm about to mix and one of them is noticeably quieter than the others, I will quickly gain stage that quieter one up to get it closer to the others. Once all my tracks are at what I think is a good balance in terms of gain, then I'll move on to inserts/plugins like compression and EQ and start to make adjustments to the mix with the faders in the DAW.

Big thing to remember is it's just another tool in the toolbox and isn't a 'must-do' or anything. It all depends on what you think sounds good. And there are often many ways to achieve a goal in audio engineering.