It's literally less accuracy for the price. Unless you spend at least double of your budget, there won't be better accuracy than in portable meters.
The SDM3045X is a 66,000 count DMM firmware limited on what's actually 220,000 count hardware. DC accuracy is 0.06% + 8 counts. AC accuracy depends on voltage range and frequency, but the worst accuracy is 3% + 40 counts; best case is 0.6% + 10 counts.
The Fluke 87V, is 6,000 counts standard, 19,999 counts in high-resolution mode. DC accuracy is +/- 0.05% + 1 count. AC accuracy is +/- 0.7% + 2 counts. They don't give more detailed accuracy than that, I'm sure they only listed their best accuracy. I'd love to know the true range of accuracy for it.
Bottom line, the Fluke 87V costs more, and is maybe a tiny bit more accurate in a best case scenario, while also giving up other benefits of the less expensive bench meter.
If you match the price of the Fluke 87V, you can buy the SDM3055 instead. 220,000 counts. DC accuracy of 0.015% + 0.004 count. AC accuracy best case 0.2% + 0.05 count; worst case 3% + 0.05 count.
I do agree that doubling his budget gets a much better device. The SDM3065X is 2,200,000 counts. Accuracy± (% of Reading + % of Range). Worst DC accuracy is 0.0055+0.0008. Best AC accuracy is 0.06+0.04, and worst is 4.00+0.50.