I’m tired of transferring files between my laptops and mobiles. Has anyone tried NAS? does it have any significant cons? Also please suggest some.

You can setup an RPi with Nextcloud (or even just Samba shares) and attach a 2.5 HDD/SSD to it and directly hook it up to your Router’s LAN port.

I have a RPi lying around. This could work . Thanks

Ummm..... google drive or dropbox might be a simpler solution perhaps?

But i don’t like to pay a monthly subscription and i want the files to be stored locally in my device

If you have windows you can just enable network sharing and access all your system files directly on any device connected to the same WiFi/network. You can also just copy/paste files when you want to transfer. Don't know how SMB sharing works for other OS's

I use Telegram ( Saved Messages ) for this purpose.. 😛

I use a synology DS920+ NAS. It is effectively a quad core PC with 4 hard drives that can also run a bunch of containers (Pihole, unifi controller, adguard) and VMs. It can also support RAID, so I have local backup of photos, files, projects, etc. For something cheaper, all your need is an old PC or laptop and load it up with FreeNAS or Ubuntu and enable SMB for file sharing thru samba.