I agree. I require 3.5 hours minimum when travelling on separate tickets. Here's why:

Its easy for the inbound flight to be delayed. Most delays are probably around the 30 minutes mark, but if for whatever reason the plane goes tech....2+ hour delays are not uncommon.

In that case you would arrive at AMS and would need to book a new ticket. Booking a ticket for the next flight out is crazy expensive. Probably tens of times more than what you would save by using two tickets instead of one.

When landing at AMS with 3+ hour delay due to a technical issue with the plane, you are entitled to a 300-600 euro compensation. Which is probably enough to cover most/all the cost of buying a new ticket for the next flight out. So in that case you will be covered, and it might be worth it.

On the other hand...travelling on one single ticket is so much easier and sooo much more stress-free. If there is a possibility to have just one single ticket, and the price difference is not enormous...i'd take that option.