Virtual instruments (VSTi's) can suck a lot of system resources (CPU, ..).
Especially if you use multiple VSTi's.
It's the same thing with VSTs, some of them use a lot of resources.
Depending on your PC configuration (BIOS, drivers, windows setup) the CPU can additionally be blocked by other tasks or drivers.
This is the reasons why people tweak PCs for Audio with the goal to have optimum settings for audio processing, so that the CPU is not being blocked by either weak drivers or unnecessary background tasks.
It requires some experience to find this out and fix this.

But even if everything has been optimized according to best practises, sometimes a mainboard simply has bad design, BIOS or not so good chipset. Then you can do what you want and it will fail.

Thats the reason why some people prefer to buy a turnkey system from a company which specialized on this area, picks and tests proper hardware and drivers and performs the required optimizations in the area of BIOS and Windows.

You can use tools like LatencyMon to find out blocking drivers.

Also consider, that you might have simply a project which requires higher ASIO buffer settings !!!
Nobody would ever expect that all projects need to be able to run with lowest amount of ASIO buffers.

Note, the lower the ASIO buffer size is, the higher the CPU load will be and at a certain point of CPU load you will notice that the likeliness for audio drops increases (the more likely the lower the ASIO buffer size is I tend to say).

And .. the stress for your system will additionally increase, if you use higher sampling rates as the amount of data to be processed will be much higher.

I would advice you to use ASIO buffer sizes of 128 or 256. It gives you more safety buffer and based on my experiences I can tell you that it's still possible to records i.e. over a virtual guitar amp (VSTi) even at 128 samples ASIO buffer size.
With RME driver you will have a very low RTL roundtrip time of under 10ms.
This is fully sufficient to not slow down while playing.
On my UFX+ even 256 samples are possible to use. With 13,x ms it's at the edge but still useable.

To utilize your PCs CPU in the best possible way simply:

Minimize CPU lag because a CPU needs time to wakeup from sleep states or when changing clock
- disable all power saving options in the BIOS
- disable Windows CPU core parking (maybe not on laptops because of heat), bitsum tool: "park control"
- use High Performance Energy profile
and
- disable all not required Win10 background tasks, animated apps in taskbar, apps that do smth in the background
- choose system optimization for background tasks
and
- avoid installation of add-on tools to monitor or mainboard your systems/mainboards drivers they are often badly coded producing lag
- upon software installation use always extended installation options to see / check whether some background tasks are being implemented for i.e. automatic software checks/updates. Deny it. It's not good while recording when Windows starts tasks in the background to pull software via Network. Then you get additional I/O and interrupts from your network driver.
- check for background tasks at various places in Windows 10 (task planning, autostart, msconfig)