Both of those options scale linearly and both can be forced to censor individual websites. Furthermore, proxies are by their very nature a MITM attack.

Speech.is performs frame resolution and as such cannot be forced into censoring specific sites nor become entangled in legal liability, as bit.pe and bit.no.com can.

Frame resolution offers better security guarantees out-of-the-box and will eventually be able to remove any security trade-offs.