The kinks are still being worked out of mirrorless from Canon, whereas the dSLR has enjoyed about 20 years of increasing sophistication of operation.
'What kinks?', for one example...
- users who are accustomed to covering events in low light (e.g wedding reception on the dance floor) have found that mirrorless cameras exhibit EVF lag while panning across the scene, and the sensor is gathering 'enough light' to put an image on the EVF while in the exposure simulation mode
Just as dSLR went thru evolutionary changes to improve upon the preceding designs, the same evolution needs to take place in mirrorless
- The EOS R user interface control bar was tossed out, for controls which were more similar to Canon's dSLR line
- The 60Hz EVF update rate of the early mirrorless was improved to 120Hz EVF update rate
- eye detection AF was added to the second generation of mirrorless from Canon
- the reliance on mechanical shutter to enable connection of electronic flash evolves to electronic shutter support of electronic flash
- elimination of 'rolling shutter', etc.
Whether one waits for evolution to reach a certain stage is an individual decision. Many of us have endured the loss of value and increased cost of ownership of multiple successive models of dSLR during their 16-18 year evolution, leaving a bit of reluctance to suffer the same cost of ownership increases due to the evolution of mirrorless, until the 'time is right',
...especially since being 20 years older puts many of us in the now-limited income position imposed by retirement. The choices made can differ when one is still working and expecting occasional salary increases or bonus checks to pay for the latest toys. Yes, mirrorless has some wonderful new capabilities never to be seen during dSLR use, but the mirrorless is still in the process of maturing.