All digital surveys skew heavily to a younger demographic and heavily male. You have basically captured the political opinions of the fraction of the potential electorate least likely to vote. How exactly is that worthwhile?

I don't buy that, and even if I did the flip would be worse if you look phone contact rates.

I've seen some good very large digital surveys. We do some - geared towards measuring ad recall/lift - and I find them valuable, especially a giant sample on only two recall + head to head questions

You can always ask for gender/age and weight it but that's part of what I see as the problem. so many 'traditional' surveys i see make fairly large adjustments, lots of 'looking back' at past turnout and over fitting based on personal bias. Especially when weighting from very small sub-sample xtab e.g. hispanics. im not a pollster and that's just my still fairly-insider / polling adjacent insight

Another problem with digital surveys is most of the firms do opt-in panels, like having people register to take surveys and get paid on mechanical turk. and then they weight from there. I think this is a problem. The surveys we do run inside of mobile ads, similar to Google / FB Brand Lift surveys they go after those who saw the ads or a truly random sample, not a small biased group of survey panel