Laptop keeps shutting down and struggles to boot up

Got an old Dell Latitude here—doesn't matter if it's plugged in or running on battery, it acts the exact same way. When I try a cold boot, it just dies immediately, maybe 2 or 3 times in a row. If I let it try to load macOS, it keeps cutting out during the boot process too, maybe a few times until it actually warms up a bit. If I just hang out in the BIOS for about a minute, though, it finally boots up into macOS without any issues.
I think things are getting worse because now it’s starting to shut down while I'm actually using it. I switched the graphics to "power saving mode," and strangely enough, it stopped dying mid-use.
If this is just a bad connection or some solder issue on the motherboard, is there a repair shop that can actually fix this—or should I just call it a loss?

Oh, please forgive me! When I first spotted the thread title in the forum list, I was under the impression we were discussing a vintage Honda Civic. Just disregard my little oversight regarding the word "laptop"

It sounds like you might be dealing with a faulty graphics card, though I wouldn't rule out an issue with the motherboard just yet. It would probably be best to drop it off at a local repair shop—maybe somewhere like Geek Squad—to get a professional diagnosis. If the motherboard is actually shot, honestly, it’s usually not worth throwing good money after bad...

That’s just the inevitable failure of an Apple.
You're lucky it even boots up. For many people, it won't start at all, leaving them unable to even back up their photos or documents to an external drive.
It's the motherboard—specifically, the integrated GPU has lost its connection.
This happens when you fail to clean out the cooling system at least once a year, though twice is better.
I mean the dust inside the heatsink by the fan, not just the surface.
Some units overheat regardless; they only last three to seven years, even with regular cleaning.
Temperature fluctuations kill electronics, specifically the boards and the soldered joints.
The greater the thermal swing, the faster everything fails.
There's a massive trend toward buying an Apple, yet I know plenty of people who don't need portability—they need a real desktop. Desktops are easier to clean, easier to swap the CMOS battery or parts, and far more durable than an Apple.

Every major US city has repair shops that handle this, though they rarely offer warranties because nobody can guarantee how long a fix will actually last. It could be months or years.
It depends on the cost of the Apple and its age. Is it even worth it? A new desktop might be the smarter move.