Inspiron 3668, Wireless 1707 card = slow Wi-Fi

I've searched the internet and Dell's community but can't find a definitive answer. Apologies if mine is a repeated inquiry.

In spite of recently purchasing a new modem and a new router I cannot get any speeds to my PC greater than ~35-40 Mbps. I suspect the issue is not with neither the modem nor the router as I receive ~175 Mbps on my WiFi connected phone.

Based on my searches (and hours on the phone with tech help) I'm led to believe the "culprit" is the 1707 wireless card in my PC. The card - with all drivers updated - simply can't/doesn't handle "high speed." Is that a correct assumption? 

If so:

1) Is there anything I can do about (i.e. replace the WiFI card with a better/faster one)? (I've seen this question asked on this forum but the question had no replies.)

2) If not, should I change my Cox internet service to a slower (less expensive) one? No need to have fast internet speed if my PC can't receive it, right?

Lastly, somewhat unrelated to this topic: while my PC is not brand new when I purchased it I did try to buy, within budget, the "best". SSD, additional ram, etc. Yet I now wonder: if the installed WiFi card is "old-school" and incapable of receiving speeds greater than 40 Mpbs then what good were the PC's "upgrades"?

Thanks for reading, thanks for any help. I've grown tired of searching for resolutions to questions which should have a simple answer!