Can you trademark anything? Any name? Couldn’t you just think of loads of different names and trademark them all then sell them to people?

Like what’s to stop me trademarking variations of every word and combinations etc of every word in the oxford dictionary?

Then sell the names to companies?

Like even if it costs money to do (dunno how much?) then a company like Amazon or google could still afford to do it. Not every word obviously but you know what I mean. They could come up with loads of names that might be useful to companies in the future and sell them name to said companies.