Frankly, I'm not sure why Carter was dropped so suddenly. Yes, a pretty empty batting line, but he still had value (positive WAR from 2012-2016). Maybe his post 30 drop off was significant? And yes... he did have various threads when he hit HR milestones (though maybe 40, not 30).
Vogelbach was a waiver wire chance that actually did ok for a season, but never was a long term plan.
Tellez isn't going to carry us to a WS victory, but he is hardly our weak spot either. He ranks around the middle of the pack for 1B in the league and sadly... we've had worse. I'm happy to keep him on a low cost contract while we try to find a better option.
When looking at the value someone brings to the position, you do need to keep in mind the alternatives, too. This isn't the mid-90s when high value 1Bs were a dime-a-dozen. He is basically providing the same WAR as Matt Olson for Atlanta this year and several others in that upper 700-lower 800 OPS range. If you can't get the guys at the top, a low cost middling 1B has value.