What are the advantages of a bench top multimeter?

OP, what meters do you have now?

I'm a fan of clipping on many meters, compared to just using 1 or 2 meters and having to move probes around in energised equipment.

As such, I'd suggest aiming for at least 2-3 small battery operated DMM's with limited capabilities (eg. cheap 4 digit handhelds like Aneng 8009) plus one bench meter. If you do a cross comparison of typically used voltage and current measurements each 6-12 months then you have confidence that none of your meters is loosing accuracy. The one bench meter provides all the additional functions that the smaller meters don't.

If you are in to audio then I'd recommend looking closely at the low and high bandwidth frequencies of any meter you are contemplating. If you are doing valve stuff, then perhaps look at the input resistance of the DC and AC voltage ranges, as some meters provide > 10Meg. If you may want to log some measurements then older equipment with GPIB style comms requires at least $150 extra spend for an interface adaptor, whereas USB connection to the meter will depend on what software is available for that meter.

If you get in to wanting confirmed accuracy and with > 4 digits, then purchasing a new bench meter in the future still fits in with that group of meters.