Not trying to nitpick or anything but Apple used to offer USB ports on both sides of their non-Pro laptops, but in the new ones they offer Thunderbolt ports rather than USB C. My understanding is that they only offer ports on one side to let them only need to use one Thunderbolt controller. (The Pro machines with 3/4 ports have two, one on each side.)
Everywhere I see people talk about this issue, it points to cost saving -- what saajatjha meant
https://www.cultofmac.com/705319/macbook-pro-overheats-charg...
https://www.zdnet.com/article/can-a-simple-charging-mistake-...
https://www.ibtimes.com/why-your-macbook-pro-might-be-overhe...
https://apple.stackexchange.com/questions/363337/how-to-find...
https://www.extremetech.com/computing/309802-charging-a-macb...
The funny thing is, the last time I ran into this was at work, when a colleague mentioned they only charge on the left because of this issue. I pointed out that the original post said you should charge on the right and they were left pretty red faced after that. Clearly, they didn't have any issues with charging on either side.
If you need any more evidence, just consider the fact that the macbooks that only have ports on one side have them only on the gasp left!