Having an official role in Sunday Mass I can tell you there are certain practical issues at play in our parish. In particular many elderly parishoners with walkers, canes and wheelchairs. Bringing everyone to the rail would be fraught with difficulties IMO.
Back when polio was ravaging the young in America, I remember priests exiting the altar to administer Holy Communion to those on crutches, wheel chairs and in braces. They may have been the last to receive at the Mass, but it was no great bother for priest or congregant.
1. There were plenty of elderly, disabled persons back when there were communion rails everywhere.
2. Episcopalians still receive kneeling at the rail and always have (albeit in the hand rather than on the tongue). And the Episcopalians are definitely a "graying" denomination, as most of the young families have left for churches that actually believe something.
My husband was head usher for the 11:15 service at our pre-conversion ECUSA parish. The rail itself provides support for those who merely have difficulty getting up and down. The first step makes the distance shorter, and cushions are provided. For those on crutches, walkers, or in wheelchairs, they come to the open altar gates and stand, or the priest goes to them.
In every parish I have attended Mass at, the Eucharist is brought down to those with walkers, canes and wheelchairs. They are not expected to proceed up to receive. In churches with altar rails, they could so the same.
‘Bringing everyone to the rail would be fraught with difficulties.’ Wouldn’t this always have been the case? How was it dealt with previously? Does not seem to me that their frailties need to set the rule for the entire congregation?