If your engine does not need synthetic to protect for extreme heat or slow flow when cold, then you can use conventional oil without any problems. OTOH, if you want to spend more per oil change, synthetic is perfectly fine to use.
The engine was designed with conventional oil as the prospective lubricant. It should do fine. Synthetic will not buy anything unless you reach temperature extremes where regular oil would tend to degrade.
I have yet to use any synthetic in my Kohler CVs, with conventional 10W30 as the spec'd lube. They have lasted since 1988 and 1997 respectively, don't knock or use oil between changes. I do not baby them, as they were designed to run at about 3k rpm for hours, and they do fine. When drained, the oil is still brown, not black. I use any brand, whatever is on the shelf. I have used Stens filters without problem, along with some from auto parts stores that matched.
This is not rocket science, and the oils today have better additive packages than when the engines were designed.
If you want to spend money on very very high quality oils, have at it. You are just lining the pockets of those who sell that product. Check with "Project Farm" YT channel for unbiased comparisons of oil brands. You may be surprised at which seem to perform better than some usual suspects. Oil should not cost $10/qt. If it does, a LOT of that is in profit.
IMO.
tom