Well it was Charmed so it was all kind of bad (glorious bad like camp bad, they knew their show wasn't winning any emmys). I can't speak for where you got the long hours from, considering how much the actresses were able to contribute as producers, I doubt they were ever working 14-16 hours. Hell two of the three leads weren't available for filming part of the series finale cause one of them had a shlockly horror film and the other was visiting family.
Besides it's not about it being "important". You need filler episodes or else it's just too rushed and you don't get as many good moments to build notable characters. In a weird way it's also easier to remember basic plot details if the pace isn't "plot point, plot point, plot point, three year hiatus".