Question And old 4k vs a new 1440?

[Housaiga]

So I'm doing a completely new system build with a 7800x3d and a 4090. I've been told the way to get the most out of a 4090's power over a 4080 is with 4k. I do have a 4k monitor, an ASUS TUF VG289Q but it has a 60mhz refresh rate. With my budget I could get a 1440 Dell S3222DGM which has a 165mhz refresh rate.

I play all kinds of games, from Helldivers II to Apex Legends to Final Fantasy XIV.

So which is better? Keeping the 4k 60mhz monitor or getting the 1440 165mhz monitor? Or is there a cheaper 4k option that also has a better refresh rate than my current monitor?

Or should I just save more money for a higher quality 4k in a couple of months/a year?