と言(い)うものでもないThere is no guarantee that…, Not necessarily

Both mean just because (A), it doesn’t mean (B). ことにはならない emphasizes that one condition doesn’t guarantee a result, as in 勉強したからといって合格することにはならない (Just because you studied doesn’t mean you’ll pass). というものでもない carries a stronger nuance that the claim cannot be taken as an absolute truth, as in お金があれば幸せになれるというものでもない (Having money doesn’t necessarily mean you’ll be happy).

Both reject absolute statements. というわけではない often counters an assumption with logical reasoning, as in 嫌いというわけではない (It’s not that I dislike it). というものでもない focuses more on the idea that something is not necessarily accepted as true, as in 努力すれば必ず成功するというものでもない (Effort doesn’t necessarily guarantee success).

Both というものでもない and わけではない express that something isn't necessarily true, but differ in tone. わけではない directly denies a potential assumption, while というものでもない has a more indirect or reflective nuance, often meaning 'it's not always necessarily the case that (A)'.

These two expressions are similar in meaning, but with a slightly different nuance. とは限らない says that something isn't necessarily the case, e.g. '高いものが必ずしも良いとは限らない' ('Expensive things aren't always good'). というものでもない says that something cannot be stated as a general truth, e.g. '努力すれば必ず成功するというものでもない' ('It's not necessarily true that effort always leads to success').

Both 必ずしも and というものでもない carry the meaning 'not necessarily', but are used in different ways. 必ずしも precedes a phrase or sentence to emphasize 'not always', and is often used with phrases like とは限らない, e.g. '必ずしもいいとは限らない' ('It's not necessarily good'). というものでもない appears at the end of a sentence and implies a general principle about how things are.