When one does not raise money you get questions like "how do we know you will be here in 6 months, how are you funded?". I doubt people will tell you directly "oh, we have seen you are funded we decided to give you a chance".
> raising money is sign that your business is not doing well
You can raise money to execute (a part of) a larger plans. There are various fields that have barriers to entry in terms of regulation and/or compliance. This can still be couple of FTE + costs before you can sign any deal.
> work on your startup as side project until it's already generating 1.5-2x your annual salary, in a stable way
This highly depends on the type of business. If you are for example in B2B you can't tell your customer "sorry I can meet only after 19:00 because of my other job" not to mention how you can be perceived.
I would add to reasons why you should raise money: make sure the startup has external feedback that you listen to. All founders are quite stubborn - which is good and necessary - and is hard to convince them they need to adjust/pivot/rethink things. Investors can do that, but best is to have some previous experience with the field, otherwise they can be just noise.