And please note the necessary licensing (vSphere Standard, Enterprise or Enterprise Plus) and technical limitations:
Fault Tolerance Requirements, Limits, and Licensing
vSphere Features Not Supported with Fault Tolerance
By default, FT allows only 4 VMs and a maximum of 8 vCPUs per host. These values can be changed, but it is not a product to make a large number of VMs high available. And for vSphere 6.7 Standard and Enterprise licenses, only 2 vCPUs per fault tolerant VM are possible and for Enterprise Plus 8 vCPUs per VM (versions 6.5 and 6.0 have lower limits). In addition, a dedicated 10 Gbit network is recommended for FT which should probably not be a problem in a blade infrastructure.
More unpleasant is, that for FT VMs snapshots, storage vMotion, IO filters, storage policies and a few other vSphere features are no longer possible.
So, if it's a good idea to make your VMs high available with FT depends on whether you have the appropriate licenses and wether you can live with these limitations.