You and I have the same number of hours in a day. Everyday, we wake up to 24 hours in a day. How one uses time is personal and is different for everyone.
For me, I do not spend inordinate time on my smart phone. I do not watch movies or catch-up TVs on the phone. I do not play on-line games on the phone. These two alone would reduce our precious time from what I consider as worthwhile activities. The same applies to my personal computer.
I would limit my access to Facebook and Instagram during the day. It is not time sensitive that I have to access them to see what friends and others are posting on these platforms. It can wait until it is convenient for me to do so. My Facebook is private, limited to friends I know and would like to associate with. While my Instagram account is public, I do not follow many accounts.
As to messaging applications, I have WhatsApp. I belong to two chat groups, active in one but not the second one. I limit my time on these chat groups. I do not re-post or forward links or information that were widely circulated.
Looking at my phone, I have limited number of applications on it. I have only 16 GB of memory/storage space, which is a whole lot less space for many applications and data files. With less space, I get more time on my hand for other activities not related to accessing the phone.