Elite night credits are valuable if you expect to be short on the nights required to meet your target level. For example, if you achieve 45 nights in 2025 then the 5 Elite Night Credits would be good for keeping you at Platinum in 2026. If you don't expect to be in that situation then they have almost no value (they will still count towards lifetime status).

Nightly Upgrade Awards (NUAs) are very valuable if you are visiting hotels that are a good target for them. Nightly Upgrade Awards can be thought of as a way to push yourself to the top of the queue for upgrades: a Platinum member without NUAs is going to struggle to receive an upgrade because there are so many higher level members who take priority. With NUAs, you become higher priority[1] than everyone else but upgrades are still based on availability: a good target hotel for upgrades (and therefore NUAs) is a hotel with a large number of high end rooms/suites visited during a period of low occupancy. For example, trying to use an NUA on New Years Eve in New York City is pointless, every hotel will be near capacity, whereas a hotel in Maine in October probably isn't going to be very busy.

If neither option stands out to you as a great fit, then you can wait until later in the year to decide, once circumstance pushes you towards an option. For example, you may travel more than expected this year, and find that 5 Elite Night Credits would become useful to get you to the next level at the end of the year. Some people will say to take the nights anyway as they view NUAs as worthless, my view is that NUAs are very valuable if you have the flexibility and willingness to plan your travel to make NUAs work for you. If you're a parent travelling with kids during peak seasons (when school is out) to popular locations, don't expect to get value from NUAs. I wrote a longer comment that expands on some of these points here in case you do want to try and win at the Marriott Bonvoy game.

[1] Unlike complimentary upgrades, NUAs are awarded by a Marriott owned and managed system, not a hotel, so it's not technically correct to say that NUAs make you a higher priority for upgrades, as NUAs are completely independent of complimentary upgrades. However, from the perspective of a guest, it's easiest to think of NUAs as making you higher priority for an upgrade, rather than trying to understand the nuances of the system.