Tires can be a good uprade, but you can also get in a loop of buying lots of dfferent bits of stuff and never really being happy with the setup once the newness wears off.
Tires are generally a compromise no matter which ones you get so really it's about the kind of surfaces, weather and general coniditons you ride in to whether your next set of tires is going to positivley affect the experience. They're also the only thing between you and the pavement so from a safety perspective a good set of tires is worth it.
I tend to ride and wear out the tire that comes with the bike or they are damaged beyond use. Most mid ranged bikes come with acceptable tires that will do the job. I'll only change them instantly if the bike is going somewherere or doing something that the stock tires can't do.
All the componentry is a little meaningless if you're not fit enough to take advantage, but in the end buy whatever upgrades you want with your money. The world doesn't have to agreee with your choices.
But at some point all the upgrades you spend on a bike might make you wonder if you should have saved or just brought the higher spec bike in the first place.