The short answer - YES. Air purifiers are 100% worth buying as long as you're getting an air purifier that is effective. My favorite air filters are Austin Air Purifiers https://austinair.com/shop/
These are clinically proven medical-grade air purifiers. These air purifiers were used in lower Manhattan in 2001 and in New Orleans after Katrina and we are using them in our own homes now. Their true Medical Grade HEPA filter removes 99.97% of all particles larger than 0.3 microns and 95% of all particles larger than 0.1 microns - this means a very significant reduction in indoor dust, mold, pollen, chemicals, and gasses that are blunting your body's immune system capacity.
You can read more about what they do and their effectiveness on their website.
Hope this helps!