Can investment returns ever be enough to become an active income, without the need for a salary?

Yes. However, you would need to have enough capital.

imagine going with a 100k capital and getting a 20% return. That'd be $20k. Will that be enough to survive? Likely no.

Even if u raise your capital to 300k. It'd be a 60k.

that doesn't cater for additional savings. What if you decide to commit to a property? consider these pointers and have more buffer. It may sound promising but can turn south very quickly when returns don't keep up or you have sudden increase in Expenses. ​​​

Here's a formula I have!

(Required monthly income x 12) / dividend yield = required capital

Well it has to, if not you can't ever retire now can you.

If you're asking about an early retirement or financial independence, then it's all about having enough assets early enough providing you with a decent dividend/payout to sustain your lifestyle.

So 3 things to focus on. Total invested assets, rate of return or yield, and your expenses.

Definitively, the beauty for investment income is that there is no limit to how high you can go. While our salary tend to hit a ceiling as we progress in our career.