Unless you build from scratch, and white box stores suddenly start selling a 48v version of every standard household appliance (with industrial supply chain to support that market), inverters are not going anywhere.
replyThe only place it makes sense is personal tech and computing, where USB chargers are cheap and ubiquitous, with technology replacement in 2-5 years instead of 5-10 for standard appliances.
it would probably slowly start coming out as dual ac and dc connections and start with "garage appliances" like your laundry, central ac / vac and car charger since the garage is the cheapest place to wire something into.
replyWhy not 120V DC?
replyMainly thinking 48V as that is already a standard in the marine and automotive world. AFAIK 120V DC is not a commonly used standard ? (Maybe in aviation?)
replyMost modern aircraft have a 400V 360-800Hz three-phase grid, as this allows thinner (read:lighter) conductors. There are some high voltage DC rails on some plains in the range 270VDC or ±270VDC.
replyOn the usage side for instrumentation, avionics etc. it is usually 28 VDC.
50V is the limit for "safe extra low voltage" rules. Considered to be touch safe.
reply1. It is not considered safe voltage, so you have all the downsides of the current AC grid with the downsides of high DC voltages
reply2. Nearly no equipment uses 120VDC by itself, so you would need specialized DC-DC converters that can deal with the 120VDC input to go down to usual voltages like 48VD, 24VDC or 12VDC