In terms of the debate around where to spend money, the consumer is already being loud and clear on this. The camera market is in steady decline and heading back to the sales levels of the 90's film era.
This is mainly due to pretty much all serious cameras produced in the past 6-8 years being (more than) good enough for most peoples applications, and smartphones taking over casual photography.
Hence the big push for mirrorless which is being mainly driven by the manufacturers desperation to have a shiny new thing to sell in a declining market, and reduced production costs (no mirror box, mirror, prism more electronic integration, more automated assembly), more than offering some breakthrough new value for photographers, which it doesn't.
There isn't anything wrong with mirrorless cameras ( I have a one myself), like everything else they have advantages and disadvantages, just don't expect them to make your photography better, they won't.
Are they better than dSLR's? Yes and no. Are dSLR's better than mirrorless? Yes and no.
The current hype cycle was catalyzed by Sony simply because their attempt to crack the dSLR market (with the Minolta mount alpha cameras) couldn’t dislodge the Canon / Nikon duopoly so they had to come at it from a different angle, hence mirrorless. By going all in technically and marketing wise (full frame, aggressive seeding with youtubers etc. ) Sony was able to build hype and change the conversation away from dSLR. Having had some success made the other makers feel a bit threatened and forced to respond in kind. Voila! The mirrorless camera hype cycle.
And when I say Sony had some success, I mean some. They’ve managed to grab about 12% of the changeable lens camera market. That’s much better than where they started but nowhere near what you might think given the about of hype out there on the internet.
Just remember, all this hype has much more to do with fulfilling the needs of camera makers then it does with the needs of photographers.