Route fallback issue

I have 2 interfaces
eno1 : 192.168.1.10/24
eno2 : 192.168.2.10/24

I added routes as
172.16.0.0/12 via 192.168.1.254 metric 1
172.16.0.0/12 via 192.168.2.254 metric 2

My intention : All traffic to 172.16.0.0/12 should go thru eno1. If
192.168.1.254 is not reachable (no arp entry or link down), then it
should fall back to eno2.

But this is not working. My box keeps on looking for 192.168.1.254
(i.e. sending arp requests) and never falls back.

Can anyone help?