Let’s say you want to run a sub-4 hour marathon, and know your goal marathon pace is 9:00 per mile.
Many training plans advise your long runs be done at a pace about 60-90 seconds per mile slower, i.e. do your long runs at a 10:00-10:30 pace.
While this is not a bad idea, it’s rather difficult to do if you’re also not paying any mind to the general pace of your regular midweek easy runs. While you want those runs to be low-pressure, it may not be a bad idea to also have the same “pace goal” in mind for your regular midweek runs.
If the pace is practiced everyday in 3-8 mile chunks, then trying to do it for 2-3 hours becomes less daunting.
I understand the idea of these runs being “recovery runs” where you don’t want to put yourself under any pressure other than to run.
If you don’t struggle with focus and don’t struggle to maintain pace in a marathon, then sure, don’t worry about it. Just run.
If you don’t have a pace or time goal, then of course don’t worry about it. Just cover the distance or time required. Relax.
However, there are two camps that could benefit greatly from focusing on an “easy pace” in regular runs. I just brought up the first group: People looking to nail a time goal who also have a pace in mind for easy long runs.