Agreed. I think adverse possession is very much the exception and more fool owners if they allow a place to be occupied that long and then when notified do nothing about it. If anybody sticks it out that long and with such low chances of success they deserve to own the place.
Commercial property speculation is only marginally more tolerable. However, most speculators are interested in the land value as a site for development. So, on the whole not very palatable either because it means that if planners want to develop an area that already has too much industrial or office capacity for other use, the speculators are going to stay very quiet for a long time until they get what they want which is the highest return on their investment. As for the housing market in the UK, it has made itself into a monster that is rampaging out of control.
London rents are unbelievable and since most of the formerly council owned stock was sold off or put in the hands of housing associations there is a lot of substandard property being let at ridiculous rents. The UK needs to sort it out before the government simply allows a crisis to develop for which there will be no ready solution exactly when it is needed. No doubt if it comes that far, then they will have their hands more than full with squatters given the numbers of people who will have nowhere else to go.
Ironically, immediately after WW2 they had such things reasonably well under control, my father as a housebuilder had his order book full a couple of years ahead. We actually lived on an estate for one particular reason, that was because there was a shortage of good quality, cheap property to buy until around 1970 when my parents did just that.