Thermal throttling and overheating

After a few years of use my Razer Blade laptop has started overheating/thermal throttling reaching the high 90’s Celsius. I figured the stock thermal paste needed replacing. After replacing it it still is thermal throttling and reaching high temps when using demanding programs. Never had issues with temps until now. Temps would range mid 60’s to mid 80’s while gaming depending on the game. I’ve even undervolted the processor but that doesn’t make any difference. Both fans run at max speed while gaming, both inside and out are spotless. I’m at a loss as to why it continues to overheat/throttle after applying new paste.