Tech blogs pay? Are you sure? I have a tech blog myself. The avg CPC is $0.10 - $0.20. Lately it's been super bad.
It's not always the niche that pays you good in Adsense, most of the time it's the location/country where clicks are coming... If the clicks are coming from the targeted regions, then your luck might give you a boost in Adsense... Good luck,
I noticed that payout per click depends on 2 factors, the keyword CPC & where the traffic is coming from (ex:Search or Social). Google seems to give you a full payout of the keyword CPC if the traffic is coming from the search engine, you get a higher quality of traffic coming from search verse social.
I run a few tech blogs. It's true that you can occasionally see $1 clicks and more (my max was $2.60 I think). But in general tech readers tend to be ads-blind. So that $1 click is usually offset by a very low clickthrough. In comparison, the financial niche is much better, since clickthroughs are always around $1 and the CTR is much higher.