Tor is ran by volunteers around the world. There is a finite amount of bandwidth for everybody to share. A lot of the relays are funded by human rights organizations (which is great) but also there is no real incentive for a Pleb to run one at home (outside of good will). There is also no way to prove if the majority of nodes are from malicious actors (think deep state) trying to correlate traffic (albeit hard to due). Introducing an incentive will spark a free market of relay operators. Further increasing bandwidth and decentralization.

In regards to a "slow" wallet using tor....if you infrequently open a lightning wallet (particularly on mobile) it might seem slow to start because tor has to sync the directory of relays from the Authority relays (since IP addresses change and the network is always changing). After it gets an updated list of relays it need to build a circuit (typically 4-8) relays. This takes a short amount of time. After that, the circuit typically lasts 10 minutes and subsequent payments should seem faster.

Also, some of the recent flakiness may be due to this: