According to your theory of market dominance, there should be only one type of TP available after all the 'fractional' players go to zero. Or at the very least, several 'defensible' niches - how exactly would that apply to the squares of paper you wipe your shit with? To me they look the same. They're rolls of paper on cardboard tubes that differ in price and softness.
Business goes way beyond websites.
The major brands of toilet paper are made by corporate juggernauts like Proctor & Gamble, Kimberly Clark & Georgia Pacific. It would be very hard to break into the TP market.
Okay, you say, since no two products are exactly identical, how is my talk of niches not vacuous? Because it's not enough for the products not to be identical: they must be differentiated in the mind of the market. That is, the differences must matter to at least some part of the market. If you have a small market share, and you are unable to differentiate your product from its competition in some way -- price or features or both -- your market share will go to zero. The world is littered with examples; I'm sure you can think of plenty yourself.
Ask any angel or VC you know what they think of a business plan that proposes to capture a small fraction of a huge market, without laying out a viable marketing plan for differentiating the product.
Angels and VCs want 100x+ multiple exits. Business people don't need that, or anything at all like it. What they need is a business with customers.
I humbly suggest that this might not be the tone you ought to take, and it might not be the tone you'd like to take.
Here's an entire thread for you.