MFA is a requirement of the revised Payment Services Directive (PSD2) in the EU and many banks use their apps for authorising online card payments. Its also common to use apps as 2FA for logging in to online banking or making bank transfers.
There can be alternatives in some cases (some banks offer code generating card readers, for example) but for personal accounts in particular, it would probably be difficult to operate without banking apps.
The point obviously isn't to give grocery stores more money for no reason, it's to support products that have higher quality standards.
Take poultry as an example, standards vary by county, but the differences between quality labels can be stark. Cheap poultry is often raised in tiny indoor cages and they need to be pumped full of antibiotics due to the unhealthy living conditions. On the other end of the spectrum, organic poultry is free to roam in fields and the coops are regularly moved or kept clean, avoiding the need for antibiotics in the first place.
Even if you disagree that the latter provides a better quality product, it's pretty clear that supporting brands with higher standards results in better living conditions for the animals.
Somewhat tangential, but the EU has a directive mandating electronic invoicing for public procurement.
One of the standards that has come out of that is EN 16931, also known as ZUGFeRD and Factur-X, which basically involves embedding an XML file with the invoice details inside a PDF/A. It allows the PDF to be used like a regular PDF but it also allows the government procurement platforms to reliably parse the contents without any kind of intelligence.
It seems like a nice solution that would solve a lot of issues with ingesting PDFs for accounting if everyone somehow managed to agree a standard. Maybe if EN 16931 becomes more broadly available it might start getting used in the private sector too.
There can be alternatives in some cases (some banks offer code generating card readers, for example) but for personal accounts in particular, it would probably be difficult to operate without banking apps.