if consider one is using RM 11.90/month (200gb), it is not sufficient to backup the entire iphone of 256gb storage i believe? so for backup, i supposed u backup to PC via itunes?
if it is this plan, it may be sufficient to offload some usage of photos off the iphone but it is limited in terms of its usage.
if one is going for RM 44.90/month (2TB) , it is not cheap as well.
if assume one changes iphone every 3 years or 5 years (of course if one is rich that changes iphone every year, then ignore this completely).
RM 44.90/month x 3 x 12 = rm1616.4 (3 years of ownership) - enough for 1.6 times of upgrade price to 512gb
RM 44.90/month x 5 x 12 = rm2694 (5 years of ownership) - enough for 2.6 times of upgrade price to 512gb or enough for 1.3 times of upgrade price to 1TBif one is not heavily depends on iCloud+ and prefer local storage instead, actually it is not a bad choice to upgrade to higher storage comparing to subscribing to iCloud+.
above assume that one needs to the full features of icloud+ that is enough for a 256gb iphone for full backup etc.
one may argue that he needs only RM 11.90/month (200gb) plan, then it will be:
RM 11.90/month x 3 x 12 = rm428.4 (3 years of ownership)
RM 11.90/month x 5 x 12 = rm714 (5 years of ownership) so comparing to upgrading to 512gb iphone, then it may make more sense if it is really sufficient for one in terms of usage.
ultimately, the above comparison is solely comparing the cost of icloud+ spent if one chooses it becos he does not want to spend more $$ for higher storage iphone.
if one really needs the additional benefits brought by icloud+ to them so no matter what storage of iphone he owns, he will also need icloud+ instead of the free icloud (5GB) then it is totally a different story and the comparison is not relevant.

I'm paying for 2TB. I don't want to risk missing all my photos and videos in case my phone got lost or stolen. Manual backup is too troublesome and I don't have time for that. I have around 300GB of pics and videos.