Dangerous anecdote: I put down 35% on my house, which at the time was about 20% of my net worth.

2 years later, and the stock I sold to get that 40% downpayment is now worth 8x as much – just under 3x the total value of the house.

I'd do it again because diversification is good, but hurts with 20/20 hindsight.

In regular circumstances, and if I were doing it all again, I wouldn't worry about what % of my net worth it was and put a minimum of 20% down + enough to bring the payments down to 33% of my salary.