My views on market validation have changed with age. What I've observed after talking to hundreds of founders is that it's now so easy for someone to enter a market that it seems like those that are successful are the ones who managed to _create_ their market. No matter how smart or how good your idea is, many many successful ventures are successful because of some intangible / hard-to-reproduce circumstance that allowed them to create the market. It could be investor /pr momentum, connections, regulatory friction or some other intangible, but whatever it is - it's not something that could be easily reproduced because it's nuanced for every founder and company.
Markets are formed from societal conditions, businesses emerge within that. Nobody "creates a market" - not even market makers. What you're observing is the discovery of a series of repeatable process that perfectly match the ability for 2 or more parties to exchange value in a safe and understood manner relatively to the period in time. The systems and processes are all relatively the same in most business regardless of industry or size, what differs is: nuanced for every segment and therefore SAMs, TAMs, TAMs of TAMs. Said simply: being the first to find the right product-channel-timing fit for demand that already existed in some form.
"Don't worry about people stealing an idea. If it's original, you will have to ram it down their throats."
i guess its called the unfair advantage and there is even a book by the same name!