As typical for their low-end budget board models, MSI use a cheap VRM configuration, only a few phases, made up of discrete MOSFETs, which are lacking any heatsinks.
The CPU VRM - which transforms the 12V from the PSU to the ~1V that the CPU needs - is a big cost factor, so naturally, that's one major point for the manufacturer to save money when designing the budget boards. I can't find the specifications of your board's VRM, so we have to just look at a picture of it and figure it out.
There are six chokes (the grey rectangles around the CPU socket), so that means, six phases, probably in a 4+2 configuration (4 CPU phases, two others for SA etc.). All phases use cheap MOSFETs, the four CPU phases to the left of the socket use one MOSFET per phase on the Hi-side (12V side, outside) and two per phase on the Lo-side (~1V side, inside), the two other phases above the socket just use one Hi- and Lo- MOSFET per phase. So, only the CPU Lo-side MOSFETs are doubled, not the Hi-side ones, not the chokes, and no heatsinks on anything. A VRM like this, with all components included, costs MSI probably between US$10-20.
This kind of VRM is a clear sign that this board is only intended for low-end to mid-range CPU models. A 9700K can probably approach 200W of pure CPU power draw. This is in no way something that this board's VRM can handle, unless the VRM has forced airflow perhaps with a dedicated fan. For a 9700K, you need at least a mid-range Z390 board, if not a high-end one. I posted more about that
here.
How do they make a VRM that's capable of handling CPUs with a high power draw? Well, the cheaper option is to use more VRM phases and double all the components to spread the thermal load more, and of course use heatsinks. With the 300-series boards, they used that type of concept up to pretty high board models (in later platforms, they couldn't get away with that approach anymore, as the CPUs drew even more power).
If they want to do it properly, then instead of discrete MOSFETs, they select more expensive parts called DrMOS, which combine the components (DrMOS = Driver + MOSFETs) under one roof for more efficiency. Or even better, Smart Powerstages, which not only combine all the three necessary components (driver, Hi- and Lo-MOSFET) in one small package, but also add more monitoring capability for better VRM control from the board. The variants are explained pretty well by Gigabyte
here. Powerstages have much lower switching losses than discrete MOSFETs, meaning better power conversion efficiency, so you get less heat produced in the VRM. The higher model boards also use 6- or 8-layer PCBs, so again the heat gets spread quicker and more evenly.
Compared to a simple setup with discrete MOSFETs, the DrMOS or Smart Powerstages are among the most expensive components on a mainboard. They can cost between a few dollars each to upwards of US$10 each for very high-quality ones, and you need a bunch. On upper mid-range boards you can already have US$50+ spent by MSI purely on the powerstages, not counting any of the other VRM parts like the chokes, capacitors etc. And those are not even the really expensive powerstage models. That's almost as much as the price of your entire board!
MSI simly trust on users pairing lower-end CPUs with a lower-end board model and higher-end CPUs with a higher-end board model. This is how they can even offer cheap board models to begin with. They cut down on the VRM capabilities to keep costs low, because those can be some really expensive components. That's why it's good to pair each CPU model with the appropriate board model.
The higher-up boards tend to have a bunch of other advantages, like faster and more USB ports (via additional chips), better LAN chip (2.5 GBit LAN from Realtek should cost maybe $10-20 for example), better audio chip with better components around it, integrated I/O shield, more RGB stuff, BIOS Flashback or even dual BIOS too, WLAN/BT, maybe a segment display for error codes / temperature, and whatever else. It probably does not exactly amount to what upcharge they want for the high-end boards, but of course the profit margin always gets higher, the higher you go in the line-up. Once you go to the extreme boards like the GODLIKE, it tends to become a total
money grab as of late.
But with a higher-end CPU, you should at least get a mid-range or upper mid-range board model. Otherwise, the CPU can be too much for the VRM to handle and your VRM can start to overheat, even if your CPU is adequately cooled (because the VRM generates its own heat from its switching losses). Then you'd get VRM throttling (which lowers CPU performance) or even a hard shutdown at some point.
