EMD domains will always help your search ranking, but ONLY IF you don't do anything spammy.
The reason why domain keywords will always be a factor is because you only get one shot. The words you choose for your domain are your singular expression of what your site is all about. Yes, it might be three keywords that mean something collectively, but it's pretty much the only place in your site (page title almost the same but can be longer...) where you have to be concise.
It's a shortcut for search engines to decide the topic of your site. Or the name of your brand.
The entire spammy thing is no longer valid, if it was imagine the madness, you have 10 competitors on google you can spam their sites using gsa or whatever and get them sandboxed.
I can outline a huge part of googles algorithm based on comparing results from update to update but dont have much time now.
1 spam as much as you want, but if all you got is spam you are toast
2 over anchoring, one of the silliest things people do, there is an argument of what seems natrual but some say only 5% should be anchored
3 duplicate content promoting your site
4 links only to your homepage, argument as to ratio but another silly mistake many make
5 huge burst of backlinks then total silence will get you flying down in results
6 lots of backlinks all over and 0 social media mention = google knows your bs
slow and steady wins the race, a minimum of 6 months would be needed before anyone sees any real results off SEO and thats on an avg keyword
I dont do SEO as a business, could care less either way