No landlord has been receiving $0 in rent for the last 18 months. Either they accepted rental assistance from the government (covering the full amount of missing rent) or they have declined rental assistance from the government, and have evicted the tenant. The most strict eviction moratorium is in California, which bars "evictions if renters file a declaration about their financial hardships, and if they pay at least 25% of their debt by the end of January 2021."
Also, unless the landlord entered a 2 year lease with a tenant in February 2020, why would a landlord choose to renew a lease with a tenant who is paying $0? These eviction moratoriums do not just let any tenant stay and pay $0, there are very strict guidelines for what kind of tenants are not allowed to be evicted and for how long.
Additionally, during the Great Recession, the Protecting Tenants at Foreclosure Act was passed which required 3 month notice to tenants before beginning the eviction process, so I do think it's fair to blame landlords if they are not able to afford their investment properties when a few months of rent is not paid on time.