The fielding has been bad all year, just not obviously so. At the end of the day, except for Segura, there are no elite fielders at any position - Cutch is merely better than Hoskins, and they hope Harper would (and will) be better. Hoskins is still not great at 1B, Franco is still not great at 3B. Even Realmuto isn't necessarily an upgrade, just different skill sets than Alfaro. They have to hit.
But I'm not prepared to draw any conclusions from this road trip. Even a great team is probably only going to .600 on the road and sometimes the difference between 2-5 and 4-3 is merely luck (i.e. they should have won on Friday, whether in regulation or with Nicasio not screwing up). Losing 25% of your line-up is pretty significant, especially when the hottest bench hitter (and best bench fielder) also goes down. We'll see what the next two hold, 3-4 is still possible.