Or if you were arguing for increasing the number of relays in a circuit, that doesn’t increase security. It’s like one of the OG tor research papers deciding on 3. Bad guy just needs the first and the last. Middle irrelevant.
The reason that there are so few relays and exit nodes is that everyone that runs an exit node believes, for very good reason, that they'll be opening themselves up to subpoenas and arrest for operating one. You know who never has to worry about getting arrested? Surveillance agencies tasked with running exit nodes.
Consider the two classes of relay and exit operators:
1. People who operate relays and exit nodes long term, spending money to do so with no possibility or expectation of receiving money in return, and opening themselves up to legal liability for doing so, whose only tangible benefit comes from the gratification of contributing to an anonymous online network
2. Government agencies who operate relays and exit nodes long term, spending government allocated money to operate servers, with no material risk to the agencies and whose tangible benefit comes from deanonymizing anonymous users. Crucially, the agencies are specifically tasked with deanonymizing these users.
Now, I guess the question is whether or not you think the people in group 1 have more members and more material resources than the agencies in group 2. Do you believe that there are more people willing to spend money to run the risk of having equipment seized and arrest for no gain other than philosophical gratification than there are government computers running cost and risk free, deanonymizing traffic (which is their job to do)?
Because of timing attacks? There are ways to mitigate timing attacks if you are patient (but I think clearnet webservers are not very patient and my drop your connection)
And yeah mitigation gets you into a huge body of research that’s inconclusive on practical usability. Eg so much overhead that it’s too slow and 10 people can use a 1000 relay network and still get just 1 Mbps goodput each. Contrived example.
People need to actually be able to use the network, and the more people the better for the individual.
There’s minor things tor does, but more should somehow be done. Somehow…