The problem with those small fish are that they are usually social fish and are better in larger numbers. The "magic" number is often given as 6 fish. Fish in numbers comes with more waste, and more waste needs more water volume to manage that waste. These small schooling fish also need a certain amount of swimming space.
So, your 17 litre tank will just about support 6 chili rasboras. But its not ideal.
Really the best fish option would be 1 betta. They arent social and it would be happier on its own. They arent active swimmers and dont have big territories either. So a betta in a 5g ticks a lot of boxes.
If you dont like these options other small fish in a smallish group would be OK in 5g. Neon tetras or celestial pearl danios for instance. By OK i mean they will survive, but not thrive.
Or 2 or 3 guppies. If you wanted something different and can find them maybe 2 or 3 killifish. I know people that keep pairs of sparkling gourami in 5g tanks. Again not ideal but you could make it work.
You have previously said you dont fancy shrimp, but thats a really good option for a 5g.
No-one can really tell you what you can or cant do. Its really down to yourself. We can advise on whats personally worked for us or commonly accepted as good practice.
What it seems to me is you dont really like the good options available for the tank you have. Perhaps an upgrade to something a little larger is what you really need to consider.
