If I have to rely on another person to provide me with the block chain data, that is clearly the need for a trusted third party.
As long as there is no force barring you from firing up a node of your own, your criteria of access to trustlessness is satisfied. If you are unwilling to spend the rather negligible amount of money required to do so, that is not a fault of the system.
You are talking to someone who has been running a node on dedicated hardware 24/7 for 6 years now.
I know the costs of running a node, and those costs absolutely dwarf, like it's not even in the same fucking universe, the money I've spent on transaction fees. I won't even count the time spent maintaining the node.
I've had to upgrade to a different ISP already because my node was eating all the upload bandwidth on my home internet to the point where browsing the web was unusable. I'm talking about top tier internet from a major ISP in a densely populated location.
I've spent less than $10 on transaction fees since 2011, and I've been generous (paying more than average since I mined myself). I paid transaction fees when blocks were empty and others were paying nothing.
So sell your we-need-to-increase-capacity-now-so-transaction-are-fast-and-cheap to someone else. If you want to spit on the people who have been supporting the network for years, so be it. Oh that's right, I was told today, by a BU supporter, that 3 nodes is fine.