fTPM is more secure against _this_ kind of attack, with physical access to the bus wires. However, since fTPM is a Firmware-TPM, it is vulnerable to all kinds of attacks on the system's firmware, even remotely, even via the network, even maybe if the computer is switched off. Remember all those (even unauthenticated, remote) XML-parser exploits in the Intel ME? fTPM is just one more ME module, and of course vulnerable to those exploits.
So overall, I consider fTPM a huge step back, because you might even get access without physical presence. For an fTPM, attack surface is far larger (because all of the ME software), minimum attack complexity may be smaller (because there will one day be a metasploit module for all those software problems, whereas HW hacking is always a certain hurdle), required attacker privileges are less (prolonged unobserved physical presence vs. network). Thus objectively worse in all aspects.
What would be better would be a dTPM that is integrated e.g. into a SoC, such that there are no exposed wires anywhere without decapping the SoC. Some systems such as phones work like that, but this is hard to tell even from the technical specs.