My landlord is not ready to sell the building to a builder for re-developing

Background of my landlord: My building's landlord has been absent for approximately 15 years, during which time he neither collected rent nor made any repairs. Following the COVID-19 pandemic, his descendant emerged and began requesting rent payments. All the tenants agreed to the requested rent and paid in cash, as there is no bank account for the building. Present situation: The building's condition has significantly deteriorated over the years. While it is repairable, none of the tenants are willing to invest the necessary funds due to its poor condition and the potential for redevelopment. The landlord, likewise, shows no interest in repairs or maintenance, solely focusing on collecting rent, which he insists must be paid in cash. Currently, a builder is interested in redeveloping our building as part of a larger project. They have already acquired the adjacent four buildings, leaving ours as the only remaining property. The majority of tenants (13 out of 17) have given their consent for redevelopment. However, the landlord is reluctant to agree, despite the builder offering appropriate compensation. He is disregarding our requests for repairs or redevelopment, thereby hindering any progress. Kindly suggest how can we move forward with redevlopment