I'm looking forward to reading some insightful answers as I think it's an important question.
I wonder if those who have truly discontinued their search are just no longer active here.
Perhaps worth re-asking to learn about where do deals tend to fall through more often? Doesn't mean the searchers terminated the search but just had promising deals fall through and we can learn from it.

Not terminated our search, but are after 24 months. Key theme that applies to us and other funded searchers (I hear it from conversations) in Europe is that being funded might actually be a disadvantage, as you need to buy a company of min. of[redacted]M USD/ EUR of EBITDA, which is small in US, but in Europe it already attracts interest from buyers and sellers are usually "spoiled". If not funded, then buying a company of few hundred ths. of EBITDA, using FFF money could be potentially easier, as valuations are lower, sheer # of opportunities is larger and potential upside IRR-wise also higher (as smaller company quite often is less professional). On the other hand, the $$$ value of upside is smaller and small company is easier to go down if you make mistakes as first time CEO. Having said all that I would still have decided to go funded if I were to do this again. Just food for thought.