Yep, we've used holiday homes for around 25 years, UK and abroad, mostly very good, some exceptional and over the top, and very few poor ones.
But sadly, the last couple have been terrible, both UK, and both very expensive in sought after tourist locations.
In one the "cleaning" was abysmal, cobwebs hanging from the ceilings and door frames, and we had to move a bed which was up against the bedroom wall and found all sorts down the gap, including layers of dust, cobwebs, a couple of fluffy kids' toys and some underwear! That bed hadn't been moved to dust/vacuum for years!
In the other, the carpets were all stained and worn, no doormat at the front door, so everyone would be trailing in the muck off their shoes. Patio was absolutely lethal as it clearly hadn't been power-washed/scrubbed for years and had layers of slippy mould/growth on it, which made it impossible to go out of the patio doors into the garden.
Despite having longer to do cleans and turnarounds after covid, standards do seem to be slipping, which isn't acceptable when prices have gone up so much and they expect you to strip your own beds etc these days.
"Welcome packs" have always been variable. They're usually just the basics of milk, tea/coffee, sugar and biscuits (usually individually wrapped rather than loose or in big packets). Some are tight and give nothing at all. Others are pretty generous and include a loaf of bread, carton of milk, packet of biscuits, bottle of wine etc. A couple have left a few coffee machine pods as well. The best, I think, was a "welcome pack" that much have been worth £40! It had a couple of packs of local biscuits, a decent bottle of wine, pack of local butter, pack of filter coffee, box of local tea bags, jar of jam from a local farm shop, couple of bottles of lager, etc. It was also well stocked with other things such as decent quality shampoo and shower gel in all the bathrooms, full packs of dishwasher tablets and washing machine pods, more loo rolls than we'd ever need. Quite unbelievable really - it was also spotlessly clean and everything worked. We'd go back in a heartbeat (Not ridiculously expensive either!).