If the exhaust mechanism is attached to an above the range microwave, it’s not adequate. And that is the vast majority of kitchens I see on Zillow, and I have probably sifted through thousands and thousands of houses.
A dedicated exhaust hood is seen in very few home listings, mostly in new higher end homes, or older renovated homes.
A lot of 90s+ builders are trying to prevent any and all air leaks, many with the idea of insulation, with the outer vapor barrier system already blocking 90% of what would get through on and older house, on top of the fastest building process being sealing every visible seam and line with caulk instead of trying to cut and match it up perfectly. And any overall airflow problems are quite literally not their problem, that all goes onto the HVAC guys/company or lack thereof, which often these days are the cheapest possible corporate scrapings for employees that only have half a clue what they are doing and only really care about whether the system turns on or not as per the system manual.