The most surprising thing is that in an important by election where EVERY vote counted 53% still did not vote. We seem to have lost faith in politicians, teachers, doctors, lawyers, judges, the media, the law, social workers, the NHS etc, etc. Something has gone wrong, badly wrong.The most surprising thing was that it wasn't that close in the end.
As you say, it is likely to be close, unless there's a complete collapse somewhere. By the next election, Labour will have had some years in power, and almost no others will have a tranche of MPs with experience.