There really is nothing to fear. Firstly, there will always be more windows than window cleaners in the world, secondly, there are several reasons why a human brain makes a purchasing decision, and price isn't the only one.......level of service, whether or not you 'buy' into the service provider and quality of cleaning.
There will always be new entrants into the marketplace, no matter what sector you're in. And the smart, well organised businesses will prevail.
If these new entrants, raise the standards of the industry with new signwritten vans, that's gotta be better than the scruffy chain smoking dole cheats who use milk crates to stand on !! Not to mention make some wc's think twice about 'dumping', often without notification, some customers 'cos they can clean another house quicker or for more money in another street !