THE INCREASE IN INTERNET OR BROWSING SPEED

I HAVE BEEN USING CLOUDFLARE 1.1.1.1 FOR A WHILE BUT, LATELY KEEP GETTING DISCONNECTED USING IPHONE CELLULAR HORSPOT ON MY MACBOOK. I CHECKED THE LOG FOR MY VPN APP AND GOT THE MESSAGE AS THIS "  

[23-6-22 17:59:53] Astrill desktop version 3.9.0.2180 (64-bit)
[23-6-22 17:59:53] Operating system macOS (11.6.7)
[23-6-22 17:59:53] Detected local IP: 172.20.10.3
[23-6-22 17:59:53] Detected default gateway: 172.20.10.1
[23-6-22 17:59:53] Initiating connection with server #698
[23-6-22 17:59:54] Connecting to server #698
[23-6-22 17:59:54] Waiting for VPN interface to come up
[23-6-22 17:59:54] VPN interface utun2 is up
[23-6-22 17:59:54] Setting DNS servers to 198.19.255.254
[23-6-22 17:59:54] Flushing DNS cache...
[23-6-22 17:59:54] Showtime

[23-6-22 17:59:53] Astrill desktop version 3.9.0.2180 (64-bit)
[23-6-22 17:59:53] Operating system macOS (11.6.7)
[23-6-22 17:59:53] Detected local IP: 172.20.10.3
[23-6-22 17:59:53] Detected default gateway: 172.20.10.1
[23-6-22 17:59:53] Initiating connection with server #698
[23-6-22 17:59:54] Connecting to server #698
[23-6-22 17:59:54] Waiting for VPN interface to come up
[23-6-22 17:59:54] VPN interface utun2 is up
[23-6-22 17:59:54] Setting DNS servers to 198.19.255.254
[23-6-22 17:59:54] Flushing DNS cache...
[23-6-22 17:59:54] Showtime. "

SO HAD THECLOUDFLARE DISCONNECT AND ADD THE SYSTEM DNS TO MY DNS SERVERS ON MAC SIFI SETTING WHICH SOLVED THE PRBLEM. I WANT TO KNOW WHAT WOULD BE THE RESULT OF USING YOUR DNS SETTING INSTEAD WITH MY ASTRILL VPN APP. 

I also was shocked when I had the app disconnected and check the leack for DNS, i got the page resulting with bunch of dns server addresses from cloudflare which says if not givien to you by your vpn providr , then your dns is leaking!!!???

Then , after having your dns app set up on my system, I tried the site for leak again and got the second attachment still related to two server from cloudflare!  what is going on?