No they're not.

I run my own email server. Most spam crap cannot pass spf/dkim. Although this post has caused me to sit up and notice that the trendline is moving in the unfortunate direction, where I'd say 3 years ago the ones that pass were about 1/4, today it feels like 40-60% pass. The amount of mail I get that I expect, passes spf/dkim at around 90-95%

I suspect the delta between their any my results are the very restrictive sender rules I have prior to accept. In addition any_address@domain goes to my default mailbox, so I'm also probably selecting for laziness a bit more than most.

I also publish an email address without obfuscation on my site, which is getting very little spam, (near zero) which makes me wonder if most spam has given up on scraping the Internet for emails these days.