A laptop that runs hot, loud, and slow after a couple of years is usually doing all three on purpose: heat makes the fan spin, and throttling protects the chip. The question is which of the three layers is failing.
Layer one, airflow. Laptops that live on beds and couches pull fabric lint into the intake until the heatsink fins are felted over. If the fan noise rose gradually across months, suspect this. A can of air from the outside is a start; opening the bottom panel and clearing the fins properly is the actual fix.
Layer two, thermal interface. Factory paste dries and pumps out over years, and the gap between the die and the heatsink grows. Repasting is the single most effective laptop thermal repair, and on most models it is half an hour with the right screwdriver and a static strap. Thermal pads on the VRMs and memory need matching thickness when they are replaced, so note what came out.
Layer three, the limits. Some slim laptops are simply loud under load by design, and no amount of paste changes the acoustics. Undervolting or capping the boost can cut the noise more than any hardware work, if the software allows it.
Run a temperature read under a real load and post the numbers with the model; the shape of the curve tells the community which layer you are in.