All things being equal, no - they degrade at the same rate. Electrically you might even argue that laptops may even have an advantage due to the lower operating currents (less electromigration) and more stable source power (batteries don’t tend to oscillate), but you’re really splitting hairs at that point.
However, there are physical limitations that laptops simply cannot get around. Smaller heatsinks simply cannot hope to dissipate as much heat, smaller fans must be run faster, and smaller openings makes them more susceptible to dust. You’re also unlikely to ever accidentally cover the entire air intake with a blanket or your leg with a desktop. Plus, of course, the battery itself will degrade over time.
8GB is really the useful minimum these days. Just sitting here with a few basic programs open I’m showing 6.5GB of memory usage with minimal swapfile. While it would be possible to use 4GB (and I’ve both seen and used systems so configured) the difference in system responsiveness is very, very noticeable.
In the event the system gets used for design work, or even layout work, the usage may even go beyond what 8GB can comfortably handle. But Win10 may accommodate for that better than earlier versions due to its memory compression stuff, so I can’t say for certain whether that still holds true.
Modern CPUs have very little impact on loading times - even if large amounts of decompression are involved. Unless they’re doing parsing at scale (such as massive databases or compiling tens of thousands of lines of code), simulation (not just sim games), or content creation (video or rendering) than there will be negligible performance difference between an i3 and an i7.
The primary differences between the i3, i5, and i7 are the core counts, clock speeds, and cache. In office work situations, these aspects just don’t make that much of a difference between the top and the bottom of what’s on offer.
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In my opinion, a “good” laptop for office work would be something with either an Intel i-series or m-series, or AMD Ryzen, fit with at least 8GB of RAM (though 16GB would be nice). A Celeron may even be sufficient, but avoid AMD A-series or E-series like the plague. That’s all. Anything more specific than that is going to be a matter of taste, rather than necessity.