I just think Microsoft Word is actively making the entire world less efficient. It’s not made to produce documents that are easy to read. Don’t have an obvious contender though. LibreOffice Writer just tries to be the same shitty product but free, LaTeX is way too technical and has horrible error handling. Markdown usability and quality breaks down if you make any serious use of tables and figures.
Since I’m not a US citizen I also think it’s a threat to our country that our entire administration and every company is dependent on storing documents in an effectively proprietary format controlled by a US company, on cloud servers controlled by a US company. If compelled by the US government, Microsoft could put all of EU to a halt with the flick of a switch. National security calls for formats as central as this to be open standards supported by multiple competing products.
Sorry, I can see from the first screenshot on their web site that OnlyOffice is not conducive to legibility. A user interface that promotes direct control of the typeface (instead of styling rules based on semantic tags) is going to produce inconsistent documents.
User interfaces should be designed to make it easy to do things right, and difficult to do things wrong. This UI encourages people to produce crap.
Their other screenshots further show that they do not care about things like appropriate margin size or inter-word spacing, leaving me with little trust in the product.