The biggest GoFundMe campaign according to Wikipedia only raised $25 million in 2020 dollars (https://en.wikipedia.org/wiki/GoFundMe#Notable_projects, Bannon's et al's fraudulent We Build the Wall project). Arecibo cost $9.3 million to build in 1963 dollars (https://ethw.org/Milestones:NAIC/Arecibo_Radiotelescope,_196...), which is about $80 million in 2020 dollars. Even after one-time construction costs, millions in ongoing operating costs and maintenance would be required as well.
So, no, a GoFundMe campaign to rebuild it is not a possibility. Even hot-button political issues can't get close to the needed funds, and this is not ever going to be a hot-button issue.
Assuming the people supplying the operational funding want to continue to do so it shouldn't take more than low millions to get it going again.
Construction has a lot more costs these days - have to take care of the environment, not kill your workers...
Is a GoFundMe campaign outside of the realm of possibility? I know that I'd contribute to such a worthy effort, but only if the rest of the players would pledge to fund current operations.