The phrase "are mostly accepted as" is correct and usable in written English.
It can be used when discussing general consensus or common beliefs about a subject or concept.
Example: "These theories are mostly accepted as valid explanations for the observed phenomena."
Alternatives: "are generally regarded as" or "are widely considered to be".
Today, Constable says, the gatherings are mostly accepted as part of the city's cultural identity, thanks in part to the skilled advocacy of the Filipino activists, who then influenced the activism of a new generation of Indonesian helpers.
Chest wall PNETs, also named Askin tumours, were previously classified as a separate group of neoplasms, but now are mostly accepted as an aggressive form of Ewing sarcoma, both representing the most common malignant tumours of the chest wall in children [3].
The final SMILES, even after manual editing, adhere to the OpenSMILES specification and are mostly accepted and correctly interpreted by different cheminformatics software such as indigo-depict, Open Babel or CDK.
They were mostly accepted by their families, but their relationship was not openly discussed.
Although ROS is generally accepted as playing a role in asthma, demonstration of this in animals and humans involves mostly indirect evidence from blood, bronchoalveolar lavage fluid, and exhaled air samples.
The nursing process was mostly well accepted, as the questionnaires showed.
Thanks to multiculturalism, immigrants have less of an inferiority complex and "natives" are, mostly, more accepting of diversity, linguistic as well as racial or sexual.
One important thread that links all of these, mostly recent publications is the powerful use of knockout animals which, despite the theoretical problems raised above, are increasingly being accepted as the 'gold standard' for antibody specificity.
It is now mostly accepted that the analysis that produced these data was wrong.
