connecting our classic team sites to Office 365 groups, using the new link “Connect to an Office 365 group”

1. Classic team sites. around 85% of the sites were built using this template.
2. Enterprise wiki.

and few months ago i was confused if i should use Office 365 groups instead of classic team sites. but based on my extensive reading , i found that we should create classic team site if we want to have Site Collections with sub-sites, benefits from the full SharePoint features sets and at least the option for governance. while to use office 365 groups for social networking experience where anybody can do anything quickly and easily without involving administrators or oversight as mentioned in this link. Now lately i found that inside my classic team site i have the option to connect it to Office 365 group:-

and i read these 2 articles which talk about this feature [link1] & link24. so mainly the 2 links mentioned these benefits for connecting classic team sites to office 365 groups:-

1. A newOffice365groupis created,and that groupis connected to your site collection2. A new modern home page is created on your site andsetas the site's home page
3. The group's Owners are now the site collection administrators4.Thegroup's Owners are added to your site's Ownersgroup5.Thegroup's Members are added to your site's Membersgroup

but when i review these 5 points i found that either i do not want them OR i have already implemented the feature inside my classic team site, as follow:-

1. for point 1, i do not want this feature, as we only allow sharepoint experienced users to be the site admins.

2. for point 2, i have already created a new modern page for my classic team site and i set it as the home page. as in classic team sites we can create modern site pages and we can use the modern experience as well!!.

3. for point 3 & 4 & 5. we already have the site owners = site collection admins. so this point is not necessary,,, and i can simply add users to the current owner/member/visitor sharepoint groups to grant users the necessary permissions.

First question. so in my case, do i have to connect our classic team sites to Office 365 groups?? as i mentioned above, the benefits of doing this connection are either already achieved or not needed in our case..

second question. why i did not get the option to "Connect to an Office 365 group" inside our enterprise wiki site collection, as we got inside our classic team site?

third question. seems if we have sub-sites inside our team site.. then those sub-sites can not be connected to office 365 groups? so if we already have sub-sites inside our classic team site,, then is this another point for not doing the connection ??

can anyone advice on my above 3 questions, thanks in advance for any help and sorry for the long question.

Regards