On the office network my laptop tops out at 50 Mbit/s while my phone next to it hits 400 Mbit/s. Probably the WiFi card.

Older Intel WiFi modules cap at 802.11ac on 80 MHz, not the WiFi 6 or 6E your modern access point speaks. Replacing the internal card or adding a USB adapter is similar in effect, different in cost.

Try this first

1. 1Verify the cause. Run 'netsh wlan show interfaces' on Windows. 'Radio type' (e.g. 802.11ac) and Receive/Transmit rate show what you actually get. On Mac, hold Option and click the WiFi icon for PHY mode and Tx Rate.
2. 2Test less than 5 meters from the AP. Other devices in the same test get 400 Mbit/s? Then the client radio is the limit.
3. 3Check whether the internal card is replaceable. Many laptops have an M.2 2230 WiFi/BT module. Look up the Lenovo, Dell or HP model page. Apple Silicon and some ultrabooks have it soldered.
4. 4A WiFi-6 or 6E module (e.g. Intel AX211) costs around 25 euros, plus 30 minutes labor. Driver comes from Intel directly. Works first boot.
5. 5If replacement is not possible, use a USB adapter (USB-3, not USB-2). Cheaper, but sticks out and earbuds bump into it. Pick a chipset with stable Windows drivers (TP-Link AX1800, ASUS USB-AX56).
6. 6If you go USB: disable the internal radio in Device Manager. Otherwise Windows flips between them and you get weird connectivity issues.

None of the above fits?

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