I would not say it has massive impact, plus bolding keywords is a bit of an old school practice, but there is still some benefit / value I believe to using it, although does make content look unsightly if over used.
It's also worth mentioning that this tag **is redundant and has been for many years, you would need to use the following tag Keyword. Be careful to how much you use it and how perfect you make the SEO you do not want to get penalized for over optimisation. **
**Its best to think about this when writing content anyway
Focus content beyond basic keyword density and take into consideration advanced topic modelling - synonyms and close variants; keyword usage and intent; and semantic mark-up
Regards,**