I think it depends on your riding contritions and how well the component is sealed. With a well sealed component in good conditions the grease will remain contamination free for a long time. Coupled with the low consiquence of neglect (just replace the bad bearing not the whole component) and you might find better use for the time.

In bad conditions or poorly sealed component the grease can get contaminated fairly quickly so maintenance is more worthwhile. The bearings will last longer and so require less frequent replacement. I personally don't like removing press fit parts if I can avoid it especially if jury rigged tools are needed to do it.

There is another reason to do it. Cartridge bearings are industrial products with loads of uses. The lube requirements of a bearing used in a bicycle are different to one spinning at high speed on the end of a motor in a dry and largely clean environment. If the manufacturer just buys any old off the shelf bearings the lube may be poorly suited to bike use. In the past at least it wasn't uncommon to buy a part and find the bearings contained a small amount of very thin almost oil like lube which didn't last long if the bearing got wet. It's a good idea to replace this with a more suitable lube.