There are also genuine problems unique to LED lamps in signals that we solved with little heaters. I don't think the amount of time involved in the "sometimes"

There are also genuine problems unique to LED lamps in signals that we solved with little heaters. I don't think the amount of time involved in the "sometimes" matters so much as the fact that the new problems are readily surmountable (with many solutions both in progress and already deployed) and the fact that people use the new problems as justification for a reactionary desire to jetison the technology entirely without even trying to surmount them.