The benefit of standalone streamers and DACs are largely dedicated power supplies and better isolation / less noise. Also, both technologies get refreshed at different intervals based on innovation in the market, so some people like keeping things separate to make upgrading individual things simpler.
Regarding clocking, even if a DAC reclocks a streamer’s signal, I’ve found that the better the streamer’s clock, the more accurate outcome results because the reclocked signal is often even better than if it was given subpar timing / info.
For DAC/streamer combos under $5K, look at the Eversolo DMP-A10 and the Aurender A1000. I am an authorized dealer for both, and I can say that I am thoroughly impressed with the Eversolo DMP-A10 for the price and sonic performance, as well as its usability. The Aurender A1000 comes close in my opinion. It may actually be a tad warmer, but not as resolving and transparent as the Eversolo. Both have a really pleasant, harmonic tone and natural presentation which surprise me. Some of Aurender’s higher level digital/analog combos can sound more Hifi-ish if not paired properly with gear and cabling. The two units I mention, however, seem to work with a number of electronics and cabling combinations.