Unfortunately, keeping the DC charger plugged into the laptop when carrying it around also stands a chance of damaging the port and cable. It is absolutely true that the action of plugging in and unplugging the DC charger from the laptop does wear the DC input jack and it is one of the higher failure rates (worked in the industry 32 years). Lenovo has an improved 2 pin design on some models. Some models now use a USB 3.1 type port, but they also wear. Cycling the battery much more in not using the charger is also not a great thing either as the battery also wears over time and needs replacing.
You carry the laptop and charger separately. The ports usually last a few years unless you're unlucky. The ports can be replaced. Laptops have three methods for the port in the laptop. The best and most common is a cable and does involve disassembly of the laptop to some extent that varies. You should investigate local repair for low flat rate labor places and what they cost just to know. The laptop warranty includes the port in normal use so don't damage it by carrying it connected. The cable is a US$7 to US$20 typically. If they put the connector on a small circuit board pluggable card that is more expensive and now rare. If soldered to the motherboard, the connector is cheap, but difficult to pull off the old one by de-soldering and soldering on a new one, and some laptop repair prefer to sell you a ew expensive motherboard. Look up the dc input adaptor repair for your exact laptop just to know what it going on. Know that it is an item that fails. AC-DC adaptors fail, dc input fails, batteries weaken over time. All things you use wear over time. Mechanical wears out faster than electronics.
There isn't a lot you can do about it but if not plugged in, don't plug it in and out every 20 minutes if you can avoid it. The usb ports also wear out and usb 3 lasts longer than usb 2.