The big cloud vendors are looking for products with mass appeal or that they think will have mass appeal.
So if you are building for with a business plan that calls for a hundred of thousands of users and more as fast as possible, you will quickly come up on the radar of the cloud providers (and others).
If you find a niche to be in, you probably won't be a unicorn in 5 years, or ever, but there is good money to be made and successful businesses to create. (Not nearly as sexy)
Of course, you can still get ripped off by a company wanting to be in the same space, usually, but not always, this becomes a fight between two companies of non FAANG status, so competition is a bit fairer.
It really help to hire domain experts in your niche. They dont have to be technical at all. Just have long experience with the business domain adn be able to talk to executives and be taken seriously.
Coming in as a "hot startup" is in my experience not impressive to potential clients.
I worked for one company who did all this and they are still going strong making good money. Often in this space you can charge a lot of licenses.
I started my own several years ago and we outcompeted the legacy offering. Our biggest problem was that clients were locked into multiyear contracts with the competition, so conversion, even if interested was high, took time.