You mean the effects of polishing won't last as long, ie the paintwork won't stay smooth for long? If so, then yes. Using a proper cutting polish (rather than a filler polish like SRP) will last longer (even without wax), but I'd not recommend leaving bare paintwork unprotected.
Waxing does take more effort than applying a liquid sealant like Auto Glym Extra Gloss Protection*, but the glossy/wet look and beading won't be as pronounced as with a decent wax.
I'd probably recommend a better cutting polish (if the car hasn't been done before/for ages), and simply sealing with EGP if you want an efficient ratio of effort:results.
By all means use SRP once the paintwork is in a good enough condition that a filler polish can remedy the light marring the car will pick up from day-to-day use, but unless it's at that point already, get a polish with some "cut" first.
*I actually use EGP on my glass/lights with each wash