I've played in a no-feats game and strongly prefer it. However, I do think the game is tolerably balanced with feats and that you run into some concerns without them. It definitely tilts the playing field toward casters, and this is likely exacerbated by the SCAG cantrips. I suspect rogues become your best consistent direct damage dealers (plus warlocks for ranged). Your fighters and barbarians aren't going to keep up. In general, I think the classes are more balanced in combat with feats, but despise the hyperspecialization that comes along with them.
And on that note, I don't get the people saying martials "lack options" or "fun things to do" without feats. For starters, my fighter (as in old-school D&D) was always able to use the best weapon for the job, whether it was a longsword and shield, two-hander, polearm or longbow. All of my physical stats were high (due to bonus ASIs), so I could be good in both melee and ranged. My damage output per attack didn't suddenly drop from 2d6+15 to 1d8 when it was time to use a bow. I chose maneuvers that were versatile as well, and I used more of them; it wasn't always Trip Attack for advantage to set up -5/+10. Likewise, feats (at least those I've seen people take) don't actually provide martials with "more options" or "fun things to do." Quite the contrary: They make the martial do one thing way better than anything else.