Is Samsung SGS9+ better than i3 old laptop

Hi,

Waiting for my exercise bike but want to be ready for Zwift.

I have an old i3 2370 laptop, 6gb. I though not a bad machine but slow by todays standards,

I opened zwift & did the watch thingy.
I know a lot of bikes often but was v. Slow, even see the rendering, I guess 1 or 2 s
Fps at times.

Did the same on my SGS9+ and looked silcky smooth.

Hard to believe the phone has much more power than a full blown pc, even an old one.

Is this down to resolution & if I play on a bigger monitor will it look poor or is it simply the SGS9 power.

Before I mess finding monitors & adapter or casting device.

Is the watching only a bad test because of the number of bikes or can this often happen on normal rides.

I have a SGS7 might this be ok also.

Thanks IA