I didn’t see any issues with the SMART info, but if the hard drive is starting to cause reliability issues, I’d be replacing it (at least if it was my laptop). If the internal hard drive was also less than 1TB, I’d be replacing it - no point having a small hard drive when you can get a 250GB SSD for about £25 (or equivalent currency) online, or 500GB (SSD) for about £50.
HP 15’s aren’t the easiest to do a hard drive replacement on, but once all of the screws have been removed (watch out for hidden screws behind the feet and rubbers, as well as hidden screws in the DVD drive area) and the two halves have been separated, it’s relatively easy for a hard drive swap.
I bought a HP 15 P series laptop a while ago and in my opinion it’s time to get the 1.5TB HDD replaced with a 500GB SSD. Whilst I’m at it, I’ll replace my WLAN module (current one is 72Mbps max!) and bump up the RAM to 16GB (though apparently the motherboard needs to come out. Why make it so difficult to upgrade the RAM?!). Might as well also do the fan and thermal compound at the same time…