Donald Trump was never the master businessman that he always claims to be. The analogy I have made on many occasions is that he is to business as Hulk Hogan is to martial arts-- great at bragging about how great he is at it, made even more perfect by his association with professional wrestling. Trump failed to "close the deal" on healthcare because he ran into one of the biggest differences between deal-making in business and deal-making in politics.
In business, Trump could close a deal one at a time. X for Y, one on one. He was never the best at it, but he wasn't the worst either. The thing about business deals is that the impact of one deal on another is minimal. If I invest in you, I have less to invest somewhere else, but another business endeavor isn't likely to turn down my money just because I invested with you. Spill-over effects just aren't that big. This is part of why Trump thinks that he can handle everything with bilateral negotiations. We have seen this in his desire to work out trade deals bilaterally, and his desire to handle Obamacare replacement negotiations person-by-person.
The problem is that politics don't work that way. This is where we see the real value of something like "the spatial model," where we put policies and legislators along a line from left to right. Within the Republican Party, on the left, we have Susan Collins and Lisa Murkowski. Without them on board, the Senate Republicans would have had precisely 50 votes, with Pence casting the tie-breaker. They would have had no extra votes to spare. But, there were more Republicans nervous about how far to the right the Obamacare replacement bill had moved, including some in the House. On the right, far, far, far to the right, there was the House Freedom Caucus.
Any change Trump tried to make that moved policy to the right, to satisfy the Freedom Caucus, made the moderates even less willing to support the replacement, and any move to the left to satisfy the moderates lost the Freedom Caucus. Trump kept trying to make incremental changes to get the Freedom Caucus on board, but what Paul Ryan realized was that there was no way to get a majority, period. Why? Because any bill that would have satisfied the Freedom Caucus would have been unpalatable to the moderates (and couldn't have gotten through Senate reconciliation rules anyway), and any move to the left lost the Freedom Caucus.
Could any negotiation have solved this? Perhaps not, but it certainly couldn't have been done one-on-one, the way Trump wants, and the way business deals work. Politics don't work that way.