Reaching out is not an easy task. You need to do research, shortlisting, diversification of channels, and personalization. Ideally, you also need an SEO tool and a good CRM. On top of that, you need to follow up regularly and keep the conversation going.
That's why many brands outsource this task to influencer marketing agencies. Contrary to internal teams, agencies already have relationships with hundreds and thousands of influencers. They also have message templates and refined processes.
If you decide to partner with an influencer marketing agency, make sure it is a full-service one. In this case, you won't have to work on any aspect of the blogger outreach and can easily focus on other marketing tasks.