It really comes down to side business model, the culture of where you’re at full-time and how much you’re willing to sacrifice personally.

I never quit my day job after growing my business to ~$5m annually mainly because it’s e-commerce which is easy to automate and I’ve hired a great team.

It’s sad to say but unless you’ve cleared $15m; making a few million really isn’t a lot of money truly so I recommend that people either:

1) make their day job their first customer or an investor

2) explore lifestyle type businesses that work well with their day job meaning no travel, easy delegation, etc (ie. FBA, shopify, physical products, micro-SaaS)