Should I buy a hand grinder or an electric one?
Buy a hand grinder if you make one or two cups a day, especially for filter, since you get better burrs for the money. Buy electric if you make coffee for a household, pull espresso daily, or have any wrist or hand strain.
The value argument for hand grinders is straightforward: no motor, no gearbox, no housing to hold either, so more of the price goes into burrs, bearings and the shaft. Dollar for dollar a good manual grinder often produces a more even grind than an electric at the same price, and for pour-over, where you grind 15 to 30 g at a time and cranking takes 20 to 40 seconds, there is little downside.
Espresso changes the calculation. Fine grinding takes many more turns and much more force per turn, and it demands a stable axle to hold the gap under that load. Espresso-capable hand grinders exist and are excellent, but they cost real money, and grinding an 18 g dose fine is a genuine minute of effort. Some people enjoy that. Most people doing it twice a day, every day, eventually buy an electric.
Volume is the other decider. One or two cups a day is pleasant. Filling a carafe for three people means grinding multiple loads and cranking for several minutes, and the novelty dies quickly. If you host, or if your household drinks coffee at different times, electric wins on sheer practicality.
What to look for in each. In a hand grinder, prioritize a dual-bearing or otherwise supported axle with zero side-to-side play, because shaft wobble ruins grind evenness more than burr material ever will. In an electric, prioritize burr size, alignment and, if you single dose, low retention and a workflow that does not fight you.
There is a third answer nobody mentions: own both. A capable electric on the counter for daily espresso and a compact manual for travel and for the office covers everything, and a travel-grade hand grinder costs less than most people spend on accessories. Not necessary, but not extravagant either.