RF, sure, jn-boxes should always be designed out.
In some instances a jn-box can be useful for "star" topology.
- Jn-box takes supply & stars off to LNE each room
- Each room receives LNE via 4-8 way grid switch
- Grid Sw supply ceiling, wall, picture, floor, table lamps, projector etc
Loop-in-at-switch eliminates that jn-box - if newbuild or refurb.
Similarly smoke alarms may need to be wired in a "star" topology.
- Getting multiple wires into one terminals can be difficult
- Surface 1G jn-box w/Wago at ceiling level can make things easier
- Better, many alarm makers do a surface pattress with wiring space
Depends on the layout of the house, existing oval capacity etc.
Yes design jn-boxes out, if not try to make directly accessible.