Landers are constructed around a centerpiece that its power sources protrude from the side, while rovers power sources are usually built into the rear. Landers are a type of spacecraft built to land on a celestial body and never move from their landing site. What are the advantages of landers over rovers? Currently, I don't see very many advantages of landers over rovers, one disadvantage landers are at is they can't move. If there are any, what advantages do landers have over rovers.
Landers are simpler than rovers. A rover needs to do everything a lander can do (i.e. land) and more. Adding complexity adds weight, cost, and points of failure. If you can accomplish a goal by simply landing, it will always be easier and cheaper than landing and then moving somewhere else.
Rovers are simply not needed for all applications. Using a rover instead of a lander may be like buying a car when you don't actually need to go anywhere.
From a purely scientific perspective, there are several experiments that a rover platform cannot perform as well as a fix lander. Basically, take a look at the payload of InSight to see lander-optimized science payloads.
A lander does not move and doesn't have things like wheels, motors, suspension, rocker-bogie systems, etc. between the main body and the surface of whatever celestial body it is located on. This gives the extremely stable and (hopefully) static platform of a lander the capability to measure even the tiniest of quakes or nearby impact events using an on-board seismograph
Weather and climate monitoring
Climate and more specifically weather data is more meaningful if the monitoring station doesn't move. If, for example, you want to analyze years of climate data and during that time period the sensors you were monitoring moved to somewhere else, that would potentially invalidate your conclusions.
Astronomy and large scale planetary science
Similarly to the stability that a lander provides for a precise seismographic measurements, space observation also benefits greatly from a stable platform. A telescope on board a rover that crosses bumpy terrain isn't that useful and similar long-range high-precision experiments also don't work as well. For example, the insight lander is equipped with a radio experiment (RISE) that's designed to perform extremely exact measurements so that properties about Mars's interior can be estimated.
In addition to the mechanical and electro-mechanical complexities of rovers compared to landers: motors, gears, wheels, bearings etc. there are operational complexities with rovers.
Because of the large distances between Earth and the locations where exploratory space craft are sent there will always be a time delay in sending and receiving communications between Earth and such craft.
Getting a lander to do anything is less complicated than getting a rover to do any thing, particularly move from one location to another. With a lander all that is required is a signal and software and things happen. With a rover, a move from one location to another needs to be carefully planned by humans on Earth and those instructions sent to the rover: path of travel, speed of travel and duration of travel. Rovers are not autonomous and they do not have enough, if any, artificial intelligence to determine their owning functioning.