You could use a Joint Compound to skim the walls with than it would trquire sanding to make it smooth.
If you would like to skip the sanding & dust use a Veneer plaster product.
Examples of a Veneer to use.
(1) Master of Plaster
(2) TexSton Plaster
(3) Variance Plaster
(4) San Marco Skim Coat Plaster
All the above are a higher cost for material but can be completed faster than drywall mud plus none of the above require sanding.
Also color can be added which would not require painting.
Plastering or skimming the surface smooth and relatively in a flat plane is not an average skill. Your better bet is to cover the whole thing with 1/4" drywall. Making sure you use extensions for outlets. If you cover, and if you have "textured" ceiling as well, you probably should cover the ceiling as well because joint compound at the joints. Recreating the texture is not easy to do since the original texture has been changed with years of paint coats. There must be videos on this. See some of them to get some ideas on what to expect.
IMO skim coating a wall like that isn't a big deal. You don't need to cover the entire wall but basically just fill in the low spots. If laminating with another layer of drywall I wouldn't do the ceiling too but use crown molding to hide the gap between the wall and existing ceiling.
First sand everything to take off the high spots, preferably with a random orbital. Next, skim coat to fill in all the low spots. Finally, sand again. Then prime with a good sealer (I would use Gardz) and then you're ready to paint.
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