All this may be true; but we noticed a decline, in food quality and service, well before COVID messed up everything for everybody.
During the 90's and aughts, when I traveled on per diem, chains such as Marriott and Hampton Inn vied for business travelers' dollars. "Free Breakfast" was a coveted perk. Guests lined up at 0600-0630 for omelet stations, waffle stations, hot greasy meats (which I avoided), fresh fruit, yogurt, several kinds of boxed cereal, and granola bars that could be taken away for snacks. As others have said, I could go all day (and save my lunch per diem) on a good solid breakfast.
In later years, we shuttled back and forth on I-95 between Maryland and Florida with an overnight stay along the way. The same chains now offered Wi-Fi but in other ways were clearly shaving expenses. Many breakfast items were pre-packaged (preservatives and salt, yuck).
First the omelet stations disappeared, then the waffles (which I never liked). I still recall a Hampton Inn in Savannah GA, with smiling attendants and freshly cut fruit medley, that morphed the next year into canned fruit cocktail, with a clumsy grump, loudly banging steam trays into their supports.
We moved to Florida in 2019, necessitating several car trips, and a lot of overnights until we brought pots, put an inflatable bed in the house, and cooked there.
Breakfast was now only the cheapest calories: One kind of dry cereal, from a sort of pet food dispenser, I suppose to cut down on theft of individual boxes; toast; milk; cheap yogurt cups (two tablespoons yogurt, the rest preserves); some trays of greasy meat; liquid sugar disguised as orange juice; and a rack of bananas. No snack bars, or perhaps they were already gone. Of this "bounty," all we could stomach was coffee, cereal, milk, and sliced bananas.
Of microwaveable sandwiches, the less said, and even less eaten, the better.
Spoke with the GM of a local Marriott the other day. We talked about this very issue.
Bottom line, they can't get help. They can't serve breakfast, they can't even clean the rooms daily, just at the end of the guest's stay. It's not just his hotel, they're all (at least, around here) having the same problems.
Hotel careers are made or broken on the comments guests leave. But lately, upper management has recognized the challenges and reduced that focus. It's not the GM's fault that the web site still advertises amenities for which there are no resources to support.
On the flip side, his observation is that guests are more cranky, too. Some of it is understandable based on the missing amenities, but there's also a sharp increase in pure a-hole attitudes.
I suspect this is partly a local thing. Our regional economy is seasonal. Many foreign workers couldn't come this year, and local young people who often seek out summer jobs are not doing so. Add to that all the shortages and inability to buy, ship, install or fix appliances and materials, and everyone's nerves are shot.
