"seriously restrict" is a correct and usable phrase in written English.
You can use it to express an intense degree of limitation. For example, "The government is seriously restricting public gatherings in response to the pandemic."
It will seriously restrict the growth of your business and could damage your mental health.
At present, the cost and effectiveness of mine drainage disposal seriously restrict the reclamation utilization of mine drainage.
It seems as though a record drought helped make the fires worse, and Australia has been forced to seriously restrict personal water use.
Correspondingly, classical performers are able to supply whatever the composers need for a given piece; popular performers seriously restrict what composers can ask for.
He is philosophically committed to positions that would seriously restrict a woman's right to have an abortion, erode gun control and stall hate crimes legislation.
Universities should be exempt from a new counter-terror duty that could seriously restrict academic freedom of speech, MPs and peers have told the home secretary, Theresa May.
Disease related restrictions seem to affect quality of life the most, especially for seriously restricted respondents.
Fluidization of fine cohesive powders is seriously restricted by the strong interparticle cohesion.
It seriously restricts the realization of high performances of phased array antenna.
Photoactivity of graphitic carbon nitride (g-C3N4) is seriously restricted by high recombination rate of photoinduced charge carriers.
The fluid channeling during hydraulic fracturing has been seriously restricting the efficient development of low permeability oilfield and CBM Field.
