A domain may have multiple TXT records associated with it, provided the DNS server implementation supports this.
[2] Traditionally these text fields were used for a variety of non-standardised uses, such as a full company or organisation name, or the address of a host.
That may lead to large transactions with lots of "unnecessary" information being transferred and/or uncertainty about which TXT record to use.
It explicitly states that the interpretation of the string is context dependent, and that the data is treated as binary inside the DNS.
[9][10] The character string from a TXT record used for SPF: An example of use for DMARC: Use for site verification: Use for custom email service: Brand Indicators for Message Identification (BIMI):