When someone asks a question like could worn tires cause sluggish acceleration I have to wonder if they have someone in the family or a friend who could drive the vehicle and maybe offer a better description.
Lack of mechanical knowledge is nothing to be laughed at.
You spark plugs call for a change interval of 120k miles, so they aren’t due yet. I’d be concerned about the oil also. Do you check your oil yourself? Do you know how to check your own oil?
Changing the oil every 3k is overkill. Your engine should be spotless inside and run like a brand new engine if you are having the oil changed every 3k. My concern is that either you have an oil leak and you have been letting the oil level fall too low or your mechanic isn’t changing the oil every time you bring it in. I’m going with the former.
The engine holds about 4.6 qts of oil. You can loose about 3 qts before you start seeing the flickering oil light. If it gets that low, the oil is circulating through the engine about 4 times as often as it is meant to and that means it gets very very hot. When it gets hot like that, it breaks down much faster than normal, so oil that low with 3k on it could be as worn out as oil with 10-15k in an engine that is not leaking.
If you aren’t doing it already, start checking your oil every time you fill the gas tank. When it gets a quart low, add a quart to bring it back to the full mark. If you are using oil at a rate of 500 miles/quart or less, then have your mechanic find and repair the leak. A good place to look on this engine will be the front pulley seal. Its an easy fix, should be less than $100.
I also tend to think your engine is weak due to running the engine low on oil and causing that oil light to illuminate.
Wear in the crank bearings should not cause sluggish acceleration but low compression in the top end well could. It might be a good idea to run a compression test and determine where you stand on this before spending any money or fretting over a problem that may be an expensive fix.
At the least the compression test will answer that question.
A vacuum test could also be done as a preliminary test as it’s far easier and faster than a compression test. If you see a vacuum reading of 15" or whatever then it’s time to run a compression test and verify that you’re up the creek sans paddle.